Câu trong ảnh làm như nào các bạn ơi... BÀI TẬP VỀ NHÀ BUỔI 10 $d)~27.3^x=243$ $e)~49.7^x=2041$ g),Dạng 1: Tìm x thông thường $3^x=81$,$1.~2\frac14.(x-7\frac13)=1,5$ $2.~\frac16x+\frac1{10}x-\frac4{15}x+1=0$ $h)~3^4.3^x=3^7$ $k)~3^x+25=26.2^2+2.3^0$,$1)~3^x.3=243$,$3.~\frac{x-3}{x+5}=\frac57$,$m)~2^x.16^2=1024$ $n)~64.4^x=16^8$,$4.~\frac{44-x}3=\frac{x-12}5$ $5.~\frac{x+4}{20}=\frac5{x+4}$ $o)~2^x=16$,$6.~\frac7{x-1}=\frac{x+1}9$ $1)~5^x+5^{x+2}=650$ $2)~2^{x+2}-2^x=96~3)~2^x=32$,$4)~3^{(x+3)}=81$ $5.~2^x.16=1024$,$7.~(x-5)(x-7)=0$ 8. $6.~3+2^{x-1}=24-[4^2-(2^2-1)]$,Dạng 2: Tìm x ( x nằm cơ số),$1.~(7x-11)^3=2^5.5^2+200$ $2.~(2x-1)^4=16$ 3.,$(2x+1)^3=125$,$4.~(2x+1)^4=(2x+1)^6$ $5.~(3x-1)^{10}=(3x-1)^{20}$ 6.,$(x-6)^2=9$,$7.)(2x-5)^3=8$ $8.~x^{17}=x$ 9. (,$2x-2)^3=8$,$10.~(x-6)^2=(x-6)^3$ $11.~1+3+5+7+...+99=(x-$ End of document _,2)?,Dạng 3: Tìm x ( x nằm số mũ),$a)~2^x.4=128$ $b)~2^x-26=6$ c),$64.4^x=4^5$

Question

Accepted Answer

{"userId":5291536,"userName":"whynotchauahhh"}

Dạng 1: Tìm x thông thường

1/2(x – 7/4) – 1/3 = 1,5
=> 1/2x – 7/8 – 1/3 = 3/2
=> 1/2x – 21/24 – 8/24 = 36/24
=> 1/2x – 29/24 = 36/24
=> 1/2x = 65/24
=> x = 65/12
1/6x + 1/10x – 4/15 + x + 1 = 0
=> (5x + 3x)/30 – 8/30 + x + 1 = 0
=> 8x/30 + x – 8/30 + 1 = 0
=> (8x + 30x)/30 + (30 – 8)/30 = 0
=> 38x/30 + 22/30 = 0
=> 38x + 22 = 0
=> x = –11/19
(x – 3)/5 + (x + 7)/7 = 5
=> 7(x – 3) + 5(x + 7) = 175
=> 7x – 21 + 5x + 35 = 175
=> 12x + 14 = 175
=> 12x = 161
=> x = 161/12
(44 – x)/3 + (x – 12)/5 = 4
=> 5(44 – x) + 3(x – 12) = 60
=> 220 – 5x + 3x – 36 = 60
=> 184 – 2x = 60
=> –2x = –124
=> x = 62
(x + 4)/20 = 5/(x + 4)
=> (x + 4)^2 = 100
=> x + 4 = ±10
=> x = 6 hoặc x = –14
7/(x – 1) = 9
=> 7 = 9x – 9
=> 9x = 16
=> x = 16/9
(x – 5)(x – 7) = 0
=> x = 5 hoặc x = 7

Dạng 2: Tìm x (x nằm cơ số)

(7x – 11)^3 = 25.5^2 + 200
25.5^2 = 650,25
=> (7x – 11)^3 = 850,25
=> 7x – 11 = 9,5
=> 7x = 20,5
=> x = 2,93
(2x – 1)^4 = 16
=> (2x – 1)^4 = 2^4
=> 2x – 1 = ±2
TH1: 2x – 1 = 2 => x = 1,5
TH2: 2x – 1 = –2 => x = –0,5
(2x + 1)^4 = (2x + 1)^6
=> cơ số giống nhau => 4 = 6 vô lý hoặc cơ số = 0 hoặc ±1
=> 2x + 1 = 0 => x = –0,5
hoặc 2x + 1 = 1 => x = 0
hoặc 2x + 1 = –1 => x = –1
(3x – 1)^10 = (3x – 1)^20
=> 10 = 20 vô lý hoặc 3x – 1 = 0 hoặc ±1
=> 3x – 1 = 0 => x = 1/3
=> 3x – 1 = 1 => x = 2/3
=> 3x – 1 = –1 => x = 0
(x – 6)^2 = 9
=> x – 6 = ±3
=> x = 9 hoặc x = 3
(2x – 5)^3 = 8
=> 2x – 5 = 2
=> 2x = 7
=> x = 3,5
x^17 = x
=> x = 0, x = 1 hoặc x = –1 (nếu mũ lẻ)
(2x – 2)^3 = 8
=> 2x – 2 = 2
=> 2x = 4
=> x = 2
(x – 6)^2 = (x – 6)^3
=> x – 6 = 0 hoặc x – 6 = 1
=> x = 6 hoặc x = 7
1 + 3 + 5 + … + 99 = (x – 2)^2
Tổng dãy = (số hạng)² = 50² = 2500
=> (x – 2)^2 = 2500
=> x – 2 = ±50
=> x = 52 hoặc x = –48

Dạng 3: Tìm x (x nằm số mũ)

a) 2^x.4^2 = 128

4^2 = 2^4

=> 2^x . 2^4 = 2^7

=> x + 4 = 7 => x = 3

b) 2^(x – 2) – 26 = 6

=> 2^(x – 2) = 32

=> 2^(x – 2) = 2^5

=> x – 2 = 5 => x = 7

c) 64.4^x = 4^5

64 = 4^3

=> 4^3 . 4^x = 4^5

=> x + 3 = 5 => x = 2

d) 27.3^x = 243

27 = 3^3, 243 = 3^5

=> 3^3 . 3^x = 3^5

=> x + 3 = 5 => x = 2

e) 49.7^x = 2041

49 = 7^2, 2041 = 7^4

=> 7^2 . 7^x = 7^4

=> x + 2 = 4 => x = 2

h) 3^4 . 3^x = 3^7

=> 3^(4 + x) = 3^7

=> 4 + x = 7 => x = 3

i) 3^x . 3 = 243

3^(x + 1) = 3^5

=> x + 1 = 5 => x = 4

k) 3^x + 25 = 26.2^2 + 2.3^0

=> 3^x + 25 = 104 + 2

=> 3^x + 25 = 106

=> 3^x = 81

=> x = 4

l) 3^x . 3 = 243

=> x = 4 (giống i)

m) 2^x . 16^2 = 1024

16^2 = 2^8, 1024 = 2^10

=> 2^(x + 8) = 2^10

=> x + 8 = 10 => x = 2

n) 64.4^x = 16^8

64 = 4^3, 16^8 = (4^2)^8 = 4^16

=> 4^(x + 3) = 4^16

=> x + 3 = 16 => x = 13

o) 2^x = 16

=> 2^x = 2^4 => x = 4

5^x + 5^(x + 2) = 650
=> 5^x (1 + 25) = 650
=> 26.5^x = 650
=> 5^x = 25 => x = 2
2^(x + 2) – 2^x = 96
=> 4.2^x – 2^x = 96
=> 3.2^x = 96
=> 2^x = 32 => x = 5
2^x = 32 => x = 5
3^(x + 3) = 81
=> 3^(x + 3) = 3^4
=> x + 3 = 4 => x = 1
2^x . 16 = 1024
16 = 2^4, 1024 = 2^10
=> 2^(x + 4) = 2^10
=> x + 4 = 10 => x = 6
3 + 2^(x – 1) = 24 – [4^2 – (2^2 – 1)]
=> 4^2 – (2^2 – 1) = 16 – (4 – 1) = 16 – 3 = 13
=> 24 – 13 = 11
=> 3 + 2^(x – 1) = 11
=> 2^(x – 1) = 8
=> x – 1 = 3 => x = 4