Question

Решите уранение)
5x²+5x-15=2x²+11+9

Answer 1

5x²+5x-15=2x²+11x+9
5x²-2x²+5x-11x-15-9=0
3x²-6x-24=0 |:3
x²-2x-8=0
D=4-4*1*(-8)=4-(-32)=$\sqrt{36}$ = 6

$x_{1} = \frac{2+6}{2} = \frac{8}{2} =4$

$x_{2} = \frac{2-6}{2} = \frac{-4}{2} = -2$