Question

equaçao 2(x²-1)=x²+7

Answer 1

 2(x²-1)=x²+7
2x² -2 = x² + 7
2x² - x² -2 -7=0
x² - 9 =o
x² = 9
x= +ou - 3

Answer 2

2(x²-1)=x²+7
2x² - 2 = x² + 7 
2x² - x² = 7 + 2
x² = 9
x = $\sqrt{9}$
x = 3