Question

x^4-3x^3-28x^2的因式分解

x^2+(p+q)x+pq型式子的因式分解
(1)3m^2-3m^2-60m
(2)x^4-3x^3-28x^2
(3)10*(y+1)^2-29(y+1)+10

Answer 1

(1)3m^3-3m^2-60m
=3m(m^2-m-20)
=3m(m-5)(m+4)
(2)x^4-3x^3-28x^2
=x^2(x^2-3x-28)
=x^2(x-7)(x+4)
(3)10*(y+1)^2-29(y+1)+10
=[2(y+1)-5][5(y+1)-2]
=[2y-3][5y+3]