Question

Найдите корень уравнения (x-5)^2=(x+10)^2

Answer 1

(a-b)²=a²-2ab+b²
(a+b)²=a²+2ab+b²

(x-5)²=(x+10)²
x²-10x+25=x²+20x+100
x²-x²-10x-20x=100-25
-30x=75
x=75:(-30)
x= -2.5