Question

решите уравнение:
x^2/x^2-9=x/x^2-9

Answer 1

крест накрест 
(x²-9)(x²)=(x²-9)(x)
x^4-9x²=x³-9x
x^4-x³-9x²+9x
x(x³-x²-9x+9)=0
x((x³-x²)-(9x-9)=0
x((x²(x-1)-9(x-1)=0
x(x-1)(x²-9)=0
x=0
x-1⇒x=1
x²-9⇒x=+-3