Question

TÌM X biết:

a. (5x - 2)(5x + 2) - (5x + 3)(5x - 4) = 8

b. (4x - 3)( 4x + 2) + (4x + 5)(1 - 4x) =2.5²

Answer 1

a) \(\left(5x-2\right)\left(5x+2\right)-\left(5x+3\right)\left(5x-4\right)=0\)

\(\Leftrightarrow5x+8=8\)

\(\Leftrightarrow5x=8-8\)

\(\Leftrightarrow x=5.0\)

\(\Leftrightarrow x=0\)

b) 

Answer 2

câu b sao bạn

Answer 3

\(\left(4x-3\right)\left(4x+2\right)+\left(4x+5\right)\left(1-4x\right)=2.5^2\)

\(16x^2+8x-12x-6+4x-16x^2+5-20x=50\)

\(-20x-1=50\)

\(-20x=51\)

\(x=\frac{-51}{20}\)

Vậy \(x=\frac{-51}{20}\)

Answer 4

thanks b kudo shinichi