Question

x²+a²=(a+×)²-a(a-1)​

Answer 1

Despejando x:

x²+a²=(a+×)²-a(a-1)
x²+a²=(a²+2ax+x²) -a²+a
x²+a² = 2ax+a+x²
2ax=a²-a
x= (a²- a) / 2a
x= a(a-1)/2a

x=(a-1)2