Question

因式分解；a的2次方-4ab+3b的2次方+2bc-c的2次方

Answer 1

1、a^2-4ab+3b^2+2bc-c^2

=(a^2-4ab+4b^2)-(b^2-2bc+c^2)

=(a-2b)^2-(b-c)^2

=[(a-2b)-(b-c)]*[(a-2b)+(b-c)]

=(a-3b+c)(a-b-c)

2、x^2-6xy+9y^2-10x+30y+25

=(x-3y)^-10(x-3y)+25.(把（x-3y）看做整体)

=[(x-3y)-5]^2=(x-3y-5)^2