help meeeee A. ĐẠI SO:,Dạng 1: Tính, tính hợp lí,Bài 1. Tính hợp lý (nếu có thể):,$1)~(-12)+89+(-28)$ $2)~(-5)+(-75)+100+(-20)$,$3)~(-56)+74+(-14)+56$ $4)~(-27)+(-208)+(-43)+(-102)$,$5)~(-105).19+(-76).105-5.105$ $6)~140+4.119-4.19$,$7)~(2022-129+537)-(-129+637)$ $8)~(2022-3015)-(85-2022)-(-500)$,$9)~2814:14-(23.52-156).2$ $10)~[516-(25.4+16)]:8-68$,$11)~5.32+60:2^2-(6-11)^2$ $12)~160-10[128-(3-12)^2]-(-2024)^0$,$13)~5.6^2+240:4^2-3.(12-17)^2$ $14)~1-2+3-4+...+99-100$,Dạng 2: Tìm x,Bài 2. Tìm x, biết:,$1)~12-(x+20)=64$ $8)~2(x-51)=2.2^3+20$,$2)~124-x=-16$ $9)~15+(x-1)^3=42$,$3)~4-x=-27-(-15)$ $10)~(x-1)^2=4$,$4)~20-5.(2-x)=45$ $11)~7+5.(x-1)^2=87$,$5)~2(x+3)-48:2^3=2$ $12)~(x^2-4)(2x+10)=0$,$6)~200-(2x+6)=4^3$ $13)~7^{2x-6}=49$,$7)~135-5(x+4)=35$ $14)~4^x+2^{2x+1}=48$

Question

Accepted Answer

Bài 1.
1) $(-12) + 89 + (-28)$
   = $(-12) + (-28) + 89$
   = $-40 + 89$
   = $49$

2) $(-5) + (-75) + 100 + (-20)$
   = $(-5) + (-75) + (-20) + 100$
   = $-100 + 100$
   = $0$

3) $(-56) + 74 + (-14) + 56$
   = $(-56) + 56 + 74 + (-14)$
   = $0 + 74 + (-14)$
   = $74 - 14$
   = $60$

4) $(-27) + (-208) + (-43) + (-102)$
   = $(-27) + (-208) + (-43) + (-102)$
   = $-27 - 208 - 43 - 102$
   = $-380$

5) $(-105) \times 19 + (-76) \times 105 - 5 \times 105$
   = $105 \times (-19) + 105 \times (-76) + 105 \times (-5)$
   = $105 \times [(-19) + (-76) + (-5)]$
   = $105 \times (-100)$
   = $-10500$

6) $140 + 4 \times 119 - 4 \times 19$
   = $140 + 4 \times (119 - 19)$
   = $140 + 4 \times 100$
   = $140 + 400$
   = $540$

7) $(2022 - 129 + 537) - (-129 + 637)$
   = $(2022 + 537 - 129) - (637 - 129)$
   = $(2559 - 129) - (637 - 129)$
   = $2430 - 508$
   = $1922$

8) $(2022 - 3015) - (85 - 2022) - (-500)$
   = $-993 - (-1937) + 500$
   = $-993 + 1937 + 500$
   = $944 + 500$
   = $1444$

9) $2814 : 14 - (23 \times 52 - 156) \times 2$
   = $199 - (1196 - 156) \times 2$
   = $199 - 1040 \times 2$
   = $199 - 2080$
   = $-1881$

10) $[516 - (25 \times 4 + 16)] : 8 - 68$
    = $[516 - (100 + 16)] : 8 - 68$
    = $[516 - 116] : 8 - 68$
    = $400 : 8 - 68$
    = $50 - 68$
    = $-18$

11) $5 \times 32 + 60 : 2^2 - (6 - 11)^2$
    = $5 \times 32 + 60 : 4 - (-5)^2$
    = $160 + 15 - 25$
    = $175 - 25$
    = $150$

12) $160 - 10[128 - (3 - 12)^2] - (-2024)^0$
    = $160 - 10[128 - (-9)^2] - 1$
    = $160 - 10[128 - 81] - 1$
    = $160 - 10 \times 47 - 1$
    = $160 - 470 - 1$
    = $-311$

13) $5 \times 6^2 + 240 : 4^2 - 3 \times (12 - 17)^2$
    = $5 \times 36 + 240 : 16 - 3 \times (-5)^2$
    = $180 + 15 - 3 \times 25$
    = $180 + 15 - 75$
    = $195 - 75$
    = $120$

14) $1 - 2 + 3 - 4 + ... + 99 - 100$
    = $(1 - 2) + (3 - 4) + ... + (99 - 100)$
    = $-1 + (-1) + ... + (-1)$
    = $-1 \times 50$
    = $-50$

Bài 2.
1) $12 - (x + 20) = 64$

$12 - x - 20 = 64$

$-x - 8 = 64$

$-x = 64 + 8$

$-x = 72$

$x = -72$

2) $124 - x = -16$

$-x = -16 - 124$

$-x = -140$

$x = 140$

3) $4 - x = -27 - (-15)$

$4 - x = -27 + 15$

$4 - x = -12$

$-x = -12 - 4$

$-x = -16$

$x = 16$

4) $20 - 5 \times (2 - x) = 45$

$20 - 10 + 5x = 45$

$10 + 5x = 45$

$5x = 45 - 10$

$5x = 35$

$x = 35 : 5$

$x = 7$

5) $2 \times (x + 3) - 48 : 2^3 = 2$

$2 \times (x + 3) - 48 : 8 = 2$

$2 \times (x + 3) - 6 = 2$

$2 \times (x + 3) = 2 + 6$

$2 \times (x + 3) = 8$

$x + 3 = 8 : 2$

$x + 3 = 4$

$x = 4 - 3$

$x = 1$

6) $200 - (2x + 6) = 4^3$

$200 - 2x - 6 = 64$

$194 - 2x = 64$

$-2x = 64 - 194$

$-2x = -130$

$x = -130 : (-2)$

$x = 65$

7) $135 - 5 \times (x + 4) = 35$

$135 - 5x - 20 = 35$

$115 - 5x = 35$

$-5x = 35 - 115$

$-5x = -80$

$x = -80 : (-5)$

$x = 16$

8) $2 \times (x - 51) = 2 \times 2^3 + 20$

$2 \times (x - 51) = 2 \times 8 + 20$

$2 \times (x - 51) = 16 + 20$

$2 \times (x - 51) = 36$

$x - 51 = 36 : 2$

$x - 51 = 18$

$x = 18 + 51$

$x = 69$

9) $15 + (x - 1)^3 = 42$

$(x - 1)^3 = 42 - 15$

$(x - 1)^3 = 27$

$x - 1 = 3$

$x = 3 + 1$

$x = 4$

10) $(x - 1)^2 = 4$

$x - 1 = 2$ hoặc $x - 1 = -2$

$x = 2 + 1$ hoặc $x = -2 + 1$

$x = 3$ hoặc $x = -1$

11) $7 + 5 \times (x - 1)^2 = 87$

$5 \times (x - 1)^2 = 87 - 7$

$5 \times (x - 1)^2 = 80$

$(x - 1)^2 = 80 : 5$

$(x - 1)^2 = 16$

$x - 1 = 4$ hoặc $x - 1 = -4$

$x = 4 + 1$ hoặc $x = -4 + 1$

$x = 5$ hoặc $x = -3$

12) $(x^2 - 4) \times (2x + 10) = 0$

$(x - 2) \times (x + 2) \times 2 \times (x + 5) = 0$

$x - 2 = 0$ hoặc $x + 2 = 0$ hoặc $x + 5 = 0$

$x = 2$ hoặc $x = -2$ hoặc $x = -5$

13) $7^{2x - 6} = 49$

$7^{2x - 6} = 7^2$

$2x - 6 = 2$

$2x = 2 + 6$

$2x = 8$

$x = 8 : 2$

$x = 4$

14) $4^x + 2^{2x + 1} = 48$

$2^{2x} + 2^{2x + 1} = 48$

$2^{2x} + 2 \times 2^{2x} = 48$

$3 \times 2^{2x} = 48$

$2^{2x} = 48 : 3$

$2^{2x} = 16$

$2^{2x} = 2^4$

$2x = 4$

$x = 4 : 2$

$x = 2$