giải giúp tôi bài tập này Trường THCS Đạn Trường Hội - Năm học 2025 - 20.,7 $\left\{\begin{array}{l}x+y=-2(x-1)\7x+3y=x+y+5\end{array} ight.$ 25 $\left\{\begin{array}{l}3x-2y=12\4x+y=5\end{array} ight.$ 43 $\left\{\begin{array}{l}x-y=0\2x+y=-5\end{array} ight.$,8 $\left\{\begin{array}{l}2x+5y=-(x+y)\6x+3y=y-10\end{array} ight.$ 26 $\left\{\begin{array}{l}2x-y=10\5x+2y=6\end{array} ight.$ 44 $\left\{\begin{array}{l}2x+y=0\x-4y=0\end{array} ight.$,9 $\left\{\begin{array}{l}3x+y=-2\-9x-3y=6\end{array} ight.$ 27 $\left\{\begin{array}{l}5x-2y=10\5x-2y=6\end{array} ight.$ 45 $\left\{\begin{array}{l}-x+y=3\x+2y=3\end{array} ight.$,$\left\{\begin{array}{l}2x+5y=7\2x-3y=-1\end{array} ight.$ $\left\{\begin{array}{l}3x+2y=8\4x-3y=-12\end{array} ight.$ 46 $\left\{\begin{array}{l}x-y=2\3x-2y=9\end{array} ight.$,10 28,$\left\{\begin{array}{l}-x+3y=-10\2x+y=-1\end{array} ight.$ $\left\{\begin{array}{l}2x+y=-3x-20\4x+y=x-2y-12\end{array} ight.$ $\left\{\begin{array}{l}3x+y=2\6x+2y=3\end{array} ight.$,11 29 47,12 $\left\{\begin{array}{l}2x+3y=-2\3x-2y=-3\end{array} ight.$ 30 $\left\{\begin{array}{l}5x-y=1\10x-2y=0\end{array} ight.$ 48 $\left\{\begin{array}{l}2x-3y=6\4x-6y=12\end{array} ight.$,$\left\{\begin{array}{l}2x-y=3\3x+y=7\end{array} ight.$ $\left\{\begin{array}{l}3x+2y=-x\5(x+y)=-3x+y-5\end{array} ight.$ $\left\{\begin{array}{l}3x+2y=6\2x-3y=4\end{array} ight.$,13 31 49,$\left\{\begin{array}{l}2x+y=7\-x+2y=-5\end{array} ight.$ $\left\{\begin{array}{l}2x-5y=1\4x-10y=2\end{array} ight.$ 50 $\left\{\begin{array}{l}x+2y=-2\2x-y=1\end{array} ight.$,14 32,$\left\{\begin{array}{l}x-2y=-5\3x+2y=1\end{array} ight.$ $\left\{\begin{array}{l}2x+y=5\x-y=1\end{array} ight.$ $\left\{\begin{array}{l}2x+y=5\3x-y=15\end{array} ight.$,15 33 51,$\left\{\begin{array}{l}3x-2y=12\4x+3y=-1\end{array} ight.$ $\left\{\begin{array}{l}-x+2y=-4(x-1)\5x+3y=-(x+y)+8\end{array} ight.$ $\left\{\begin{array}{l}3x+2y=8\5x+2y=12\end{array} ight.$,16 34 52,17 $\left\{\begin{array}{l}-5x+3y=22\3x+2y=22\end{array} ight.$ 35 $\left\{\begin{array}{l}x+y=-1\3x-2y=-8\end{array} ight.$ $\left\{\begin{array}{l}2x+3y=5\2x+3y=1\end{array} ight.$,53,18 $\{3x+y
e0$ 36 $\left\{\begin{array}{l}0x+y=3\x-2y=-4\end{array} ight.$ $\left\{\begin{array}{l}2x-3y=5\4x-6y=10\end{array} ight.$,54

Question

giải giúp tôi bài tập này Trường THCS Đạn Trường Hội - Năm học 2025 - 20.,7 $\left\{\begin{array}{l}x+y=-2(x-1)\7x+3y=x+y+5\end{array}ight.$ 25 $\left\{\begin{array}{l}3x-2y=12\4x+y=5\end{array}ight.$ 43 $\left\{\begin{array}{l}x-y=0\2x+y=-5\end{array}ight.$,8 $\left\{\begin{array}{l}2x+5y=-(x+y)\6x+3y=y-10\end{array}ight.$ 26 $\left\{\begin{array}{l}2x-y=10\5x+2y=6\end{array}ight.$ 44 $\left\{\begin{array}{l}2x+y=0\x-4y=0\end{array}ight.$,9 $\left\{\begin{array}{l}3x+y=-2\-9x-3y=6\end{array}ight.$ 27 $\left\{\begin{array}{l}5x-2y=10\5x-2y=6\end{array}ight.$ 45 $\left\{\begin{array}{l}-x+y=3\x+2y=3\end{array}ight.$,$\left\{\begin{array}{l}2x+5y=7\2x-3y=-1\end{array}ight.$ $\left\{\begin{array}{l}3x+2y=8\4x-3y=-12\end{array}ight.$ 46 $\left\{\begin{array}{l}x-y=2\3x-2y=9\end{array}ight.$,10 28,$\left\{\begin{array}{l}-x+3y=-10\2x+y=-1\end{array}ight.$ $\left\{\begin{array}{l}2x+y=-3x-20\4x+y=x-2y-12\end{array}ight.$ $\left\{\begin{array}{l}3x+y=2\6x+2y=3\end{array}ight.$,11 29 47,12 $\left\{\begin{array}{l}2x+3y=-2\3x-2y=-3\end{array}ight.$ 30 $\left\{\begin{array}{l}5x-y=1\10x-2y=0\end{array}ight.$ 48 $\left\{\begin{array}{l}2x-3y=6\4x-6y=12\end{array}ight.$,$\left\{\begin{array}{l}2x-y=3\3x+y=7\end{array}ight.$ $\left\{\begin{array}{l}3x+2y=-x\5(x+y)=-3x+y-5\end{array}ight.$ $\left\{\begin{array}{l}3x+2y=6\2x-3y=4\end{array}ight.$,13 31 49,$\left\{\begin{array}{l}2x+y=7\-x+2y=-5\end{array}ight.$ $\left\{\begin{array}{l}2x-5y=1\4x-10y=2\end{array}ight.$ 50 $\left\{\begin{array}{l}x+2y=-2\2x-y=1\end{array}ight.$,14 32,$\left\{\begin{array}{l}x-2y=-5\3x+2y=1\end{array}ight.$ $\left\{\begin{array}{l}2x+y=5\x-y=1\end{array}ight.$ $\left\{\begin{array}{l}2x+y=5\3x-y=15\end{array}ight.$,15 33 51,$\left\{\begin{array}{l}3x-2y=12\4x+3y=-1\end{array}ight.$ $\left\{\begin{array}{l}-x+2y=-4(x-1)\5x+3y=-(x+y)+8\end{array}ight.$ $\left\{\begin{array}{l}3x+2y=8\5x+2y=12\end{array}ight.$,16 34 52,17 $\left\{\begin{array}{l}-5x+3y=22\3x+2y=22\end{array}ight.$ 35 $\left\{\begin{array}{l}x+y=-1\3x-2y=-8\end{array}ight.$ $\left\{\begin{array}{l}2x+3y=5\2x+3y=1\end{array}ight.$,53,18 $\{3x+y
e0$ 36 $\left\{\begin{array}{l}0x+y=3\x-2y=-4\end{array}ight.$ $\left\{\begin{array}{l}2x-3y=5\4x-6y=10\end{array}ight.$,54

Accepted Answer

Bài 8:
$\left\{\begin{array}{l}2x+5y=-(x+y)\6x+3y=y-10\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}2x+5y+x+y=0\6x+3y-y=-10\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+6y=0\6x+2y=-10\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x=-6y\6x+2y=-10\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}x=-2y\6(-2y)+2y=-10\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}x=-2y\-10y=-10\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}x=-2y\y=1\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}x=-2\y=1\end{array}ight.$
Vậy nghiệm của hệ phương trình là $(x,y)=(-2,1)$
Bài 9:
$\left\{\begin{array}{l}3x+y=-2\-9x-3y=6\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+y=-2\-3(3x+y)=-3.2\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+y=-2\-3(3x+y)=-6\end{array}ight.$
Hệ phương trình trên vô nghiệm
Bài 10:
$\left\{\begin{array}{l}2x+5y=7\2x-3y=-1\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}2x+5y=7\2x-3y=-1\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}2x+5y=7\8y=8\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}2x+5y=7\y=1\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}2x+5.1=7\y=1\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}2x=2\y=1\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}x=1\y=1\end{array}ight.$
Vậy nghiệm của hệ phương trình là $(x,y)=(1,1)$
Bài 11:
$\left\{\begin{array}{l}3x+2y=8\4x-3y=-12\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+2y=8\4x-3y=-12\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}9x+6y=24\8x-6y=-24\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}9x+6y=24\17x=-0\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}9x+6y=24\x=0\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}9.0+6y=24\x=0\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}6y=24\x=0\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}y=4\x=0\end{array}ight.$
Vậy nghiệm của hệ phương trình là $(x,y)=(0,4)$
Bài 12:
$\left\{\begin{array}{l}2x+3y=-2\3x-2y=-3\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}2x+3y=-2\3x-2y=-3\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}6x+9y=-6\6x-4y=-6\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}6x+9y=-6\13y=0\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}6x+9y=-6\y=0\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}6x+9.0=-6\y=0\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}6x=-6\y=0\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}x=-1\y=0\end{array}ight.$
Vậy nghiệm của hệ phương trình là $(x,y)=(-1,0)$
Bài 13:
$\left\{\begin{array}{l}2x-y=3\3x+y=7\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}2x-y=3\3x+y=7\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}2x-y=3\5x=10\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}2x-y=3\x=2\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}2.2-y=3\x=2\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}4-y=3\x=2\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}y=1\x=2\end{array}ight.$
Vậy nghiệm của hệ phương trình là $(x,y)=(2,1)$
Bài 14:
$\left\{\begin{array}{l}3x+2y=-x\5(x+y)=-3x+y-5\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+2y=-x\5x+5y=-3x+y-5\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}4x+2y=0\8x+4y=-5\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}4x+2y=0\8x+4y=-5\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}4x+2y=0\0x+0y=-5\end{array}ight.$
Hệ phương trình trên vô nghiệm
Bài 15:
$\left\{\begin{array}{l}3x+2y=6\2x-3y=4\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+2y=6\2x-3y=4\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}9x+6y=18\4x-6y=8\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}9x+6y=18\13x=26\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}9x+6y=18\x=2\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}9.2+6y=18\x=2\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}18+6y=18\x=2\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}6y=0\x=2\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}y=0\x=2\end{array}ight.$
Vậy nghiệm của hệ phương trình là $(x,y)=(2,0)$
Bài 16:
$\left\{\begin{array}{l}-5x+3y=22\3x+2y=22\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}-5x+3y=22\3x+2y=22\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}-15x+9y=66\15x+10y=110\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}-15x+9y=66\19y=176\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}-15x+9y=66\y=\frac{176}{19}\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}-15x+9.\frac{176}{19}=66\y=\frac{176}{19}\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}-15x+\frac{1584}{19}=66\y=\frac{176}{19}\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}-15x=66-\frac{1584}{19}\y=\frac{176}{19}\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}-15x=\frac{1254-1584}{19}\y=\frac{176}{19}\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}-15x=\frac{-330}{19}\y=\frac{176}{19}\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}x=\frac{22}{19}\y=\frac{176}{19}\end{array}ight.$
Vậy nghiệm của hệ phương trình là $(x,y)=(\frac{22}{19},\frac{176}{19})$
Bài 17:
$\left\{\begin{array}{l}x+y=-1\3x-2y=-8\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}x+y=-1\3x-2y=-8\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}x+y=-1\5x=-10\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}x+y=-1\x=-2\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}-2+y=-1\x=-2\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}y=1\x=-2\end{array}ight.$
Vậy nghiệm của hệ phương trình là $(x,y)=(-2,1)$
Bài 18:
$\left\{\begin{array}{l}3x+y=3\x-2y=-4\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+y=3\x-2y=-4\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+y=3\x-2y=-4\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+y=3\3x-6y=-12\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+y=3\7y=15\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+y=3\y=\frac{15}{7}\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x+\frac{15}{7}=3\y=\frac{15}{7}\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x=3-\frac{15}{7}\y=\frac{15}{7}\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x=\frac{21-15}{7}\y=\frac{15}{7}\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}3x=\frac{6}{7}\y=\frac{15}{7}\end{array}ight.$
$\Leftrightarrow \left\{\begin{array}{l}x=\frac{2}{7}\y=\frac{15}{7}\end{array}ight.$
Vậy nghiệm của hệ phương trình là $(x,y)=(\frac{2}{7},\frac{15}{7})$