Question

simplifique a expressão 7x²+2(x²-1):

Answer 1

 7x²+2(x²-1)=
 7x²+2x²-2=
 9x²-2

Answer 2

7x² + 2 . (x² - 1)
7x² + 2x² - 2
9x² - 2 = 0
9x² = 2
x² = 2/9
x = ± √(2/9)
x = ± √(2/3²)
x = ± √(2 . 1/3²)
x = ± √(2 . (1/3)²)
x = ± 1/3√2