Question

8. Решите уравнение 2(x+1)²-(x-3)(x+3)=7+x².​

Answer 1

$2(x {}^{2} + 2x + 1) - (x {}^{2} - 9) = 7 + x {}^{2}$

$2x {}^{2} + 4x + 2 - x {}^{2} + 9 = 7 + x {}^{2}$

$x {}^{2} + 4x + 11 = 7 + x {}^{2}$

$4x + 11 = 7$

$4x = 7 - 11$

$4x = - 4$

$x = - 1$