Question

tìm x biết:

b) (x-2 /9 )^3=(2 /3)^6 toán 7               c)8x-1)^2x+1=5^2x+1

giải hộ mk

 

Answer 1

b) ( x-2/9)^3=64/729

  x-2/9=4/9

x=2/3

Answer 2

8x-1=5

8x=6

x=3/4

Answer 3

b) (x - 2/9)³ = (2/3)⁶

<=> (x - 2/9)³ = 2⁶/3⁶

<=> (x - 2/9)³ = 64/729

<=> (x - 2/9)³ = (4/9)³

<=> x - 2/9 = 4/9

<=> x = 4/9 + 2/9

<=> x = 6/9 = 2/3

=> x = 2/3

Answer 4

c) (8x - 1)^{2x + 1} = 5^{2x + 1}

<=> (8x - 1) = 5

<=> 8x - 1 = 5

<=> 8x = 5 + 1

<=> 8x = 6

<=> x = 6/8 = 3/4

=> x = 3/4

Answer 5

\(b,\left(x-\frac{2}{9}\right)^3=\frac{64}{729}\)

\(x-\frac{2}{9}=\frac{4}{9}\)

\(x=\frac{2}{3}\)

\(8x-1=5\)

\(8x=6\)

\(x=\frac{3}{4}\)