Question

2(x²-1)=x²+7 me ajudem plss​

Answer 1

Resposta:

$2 {x}^{2} - 2 = {x}^{2} + 7 \\ \\ 2 {x}^{2} = {x}^{2} + 7 + 2 \\ \\ 2 {x}^{2} = {x}^{2} + 9 \\ \\ 2 {x}^{2} - {x}^{2} = 9 \\ \\ {x}^{2} = 9 \\ \\ x = + 3$

Answer 2

2(x² - 1) =x² + 7

2x² - 2 = x² + 7

2x² - x²= 7 + 2

x²= 9

x= ± √9

x= ± 3

S= ( 3 , - 3)