Question

Решите уравнение 9x^2-7(x+4)*(4-x)-(1-4x)^2=15

Answer 1

9x^2-7(x+4)*(4-x)-(1-4x)^2=15

16x^2-112-1+8x-16x^2-15=0

16x^2-113+8x-16x^2-15=0

-113+8x-15=0

-128+8x=0

x=128/8

x=16