Question

Answer 1

Giúp mình vs 

Answer 2

b, x³ + 1 = (x + 1)(2 - x)

<=> (x + 1)(x² - x + 1) = (x + 1)(2 - x)

<=> x² - x + 1 = 2 - x

<=> x² - x + x + 1 - 2 = 0

<=> x² - 1 = 0

<=> (x - 1)(x + 1) = 0

<=> x = \(\pm\)1 S = {1;-1}

c, (5 - 2x)² + 4x - 10 = 8

<=> 25 - 20x + 4x² + 4x - 18 = 0

<=> 4x² - 16x + 7 = 0

<=> 4x² - 14x - 2x + 7 = 0

<=> 2x(2x - 7) - (2x - 7) = 0

<=> (2x - 7)(2x - 1) = 0

<=> 2x - 7 = 0 hoặc 2x - 1 = 0

<=> x = \(\dfrac{7}{2};\dfrac{1}{2}\) S = {\(\dfrac{7}{2};\dfrac{1}{2}\)}

d,