Question

(×+7) (×-5)=??

Answer plz it's very urgent​

Answer 1

(х + 7)(х - 5) = х · х + 7 · х - 5 · х - 5 · 7 = х² + 7х - 5х - 35 =

= х² + 2х - 35 = 0 - это квадратное уравнение

D = b² - 4ac = 2² - 4 · 1 · (-35) = 4 + 140 = 144

√D = √144 = 12

х₁ = (-2-12)/(2·1) = (-14)/2 = -7

х₂ = (-2+12)/(2·1) = 10/2 = 5

Ответ: (-7; 5).