Question

[Trân Ni]

BT6:

A) (5x+1)^2=16/25

B) ( x - 1/3)^3=(2/3)^6

C)(8x - 1)^4=(2x+7)^4

D) (x -1)^5 =(2x-3)^5

E) ( x +1 )^8=(x+1)^10

G) (21-3)^4+(x+5)^6=0

H) 3x -4 = 81^3

Answer 1

[Phạm Thị Thanh Huyền]

a) (5x+1) ^ 2 = 4^2 : 5^ 2

( 5x+1) ^2 = (4:5) ^2

=> (5x+1) = ( 4 : 5) = 0.8

5x = 0.8 - 1

x = 0.7 : 5 

x = 0,14