Question

Сократите дробь:2х+10дробная черта х^2+х-20

Answer 1

$\frac{2x+10}{ x^{2} + x - 20}= \frac{2(x+5)}{(x-4)(x+5)}= \frac{2}{x-4} \\ x^{2} +x - 20 = 0 \\ D= 1+80=81 \\ x_{1}= \frac{-1+9}{2}= 4, x_{2}= \frac{-1-9}{2}= -5$

Answer 2

$\frac{2x+10}{ x^{2}+x-20}= \frac{2(x+5)}{(x+5)(x-4)}= \frac{2}{x-4}$→ответ.
х²+х-20=0
х₁*х₂=-20
х₁+х₂=-1
х₁=-5 х₂=4
х²+х-20=(х-(-5))(х-4)=(х+5)(х-4).