分解因式（1）(x+2)(x+4)+x^2-4(2)mn(m-n)-m(n-m)^2(3)45ab^2-20a(4)x^3y^3-4x^2y^2+4xy(5)若非零实数a,b满足4a^2+b^2=4ab,则a分之b=?

Question

分解因式
（1）(x+2)(x+4)+x^2-4
(2)mn(m-n)-m(n-m)^2
(3)45ab^2-20a
(4)x^3y^3-4x^2y^2+4xy
(5)若非零实数a,b满足4a^2+b^2=4ab,则a分之b=?

Answer 1

(1)(x+2)(x+4)+x^2-4=(x+2)(x+4)+(x+2)(x-2)=(x+2)(x+4+x-2)=(x+2)(2x+2)=2(x+2)(x+1)(2)mn(m-n)-m(n-m)^2=mn(m-n)-m(m-n)^2=m(m-n)[n-(m-n)]=m(m-n)(2n-m)(3)45ab^2-20a=5a(9b^2-4)=5a(3b+2)(3b-2)(4)x^3y^3-4x^2y^...