Решите уравнение ( 7+х)^2=(7-х)^2

Question

Решите уравнение ( 7+х)^2=(7-х)^2

Answer 1

(7+x)²=(7-x)²
(7+x)(7+x)=(7-x)(7-x)
49+7x+7x+x²=49-7x-7x+x²
49+14x+x²-49+14x-x²=0
28x=0
x=0

Answer 2

(7+х)²=(7-х)²
49+14х+х²=49-14х+х²
14х=-14х
14х+14х=0
28х=0
х=0