Question

Giúp vs cần gấp ạ

Answer 1

a. (x - 5)(x + 2) + (x + 1)(2 - x) = 15

<=> x² + 2x - 5x - 10 + 2x - x² + 2 - x = 15

<=> x² - x² + 2x + 2x - 5x - x = 3

<=> -2x = 3

<=> \(x=\dfrac{-3}{2}\)

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

<=> 25x² - 4 - 25x² + 20x - 15x + 12 = 8

<=> 25x² - 25x² + 20x - 15x = 8 + 4 - 12

<=> 5x = 0

<=> x = 0