Question

Tìm x

A( (2x+1)^2=25

B) 2^x+2-2x=96

C) 7^x+2+2.7^x-1=345

C) (x-1)^3=-125

Answer 1

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

2x+1=5

x=2

(x-1)^3=-125

x-1=-5

x=-4

 

Answer 2

a)

(2x+1)²=25

^=> \(\left[\begin{array}{nghiempt}2x+1=5\\2x+1=-5\end{array}\right.\)

=>\(\left[\begin{array}{nghiempt}2x=4\\2x=-6\end{array}\right.\Rightarrow\left[\begin{array}{nghiempt}x=2\\x=-3\end{array}\right.\)

d)

(x-1)³=-125

=> x-1=-5

=> x=-4

còn câu b và c bạn viết đề rõ hơn nha