Question

Решите уравнение (x-2)²-2(x+1)²=(3-x)(3+x)

Answer 1

$(x-2)^2-2(x+1)^2=(3-x)(3+x) \ (x^2-4x+4)-2(x^2+2x+1)=9-x^2 \ (x^2-4x+4)-(2x^2+4x+2)=9-x^2 \ x^2-4x+4-2x^2-4x-2=9-x^2 \ -x^2-8x+2=9-x^2 \ -8x+2=9 \ -8x=9-2 \ -8x=7 \ x=- frac{7}{8}$