Question

Решите уравнение.
(x+7)^2 - (x-8)^2= -15

Answer 1

$(x+7)^2-(x-8)^2=-15\x^2+14x+49-(x^2-16x+64)=-15\x^2+14x+49-x^2+16x-64=-15\14x+16x=-15+64-49\30x=0\x=0$

Answer 2

x^2+14x+49-x^2+16x-64=-15
30x-15=-15
30x=0
x=0