happy太阳
花朵
共回答了19个问题采纳率：89.5% 举报
(x^2-15x+54)(x^2+11x+28)+350
=(x-6)(x-9)(x+4)(x+7)+350
=[(x-6)(x+4)][(x-9)(x+7)]+350
=(x^2-2x-24)(x^2-2x-63)+350
设u=x^2-2x,则
(x^2-2x-24)(x^2-2x-63)+350
=(u-24)(u-63)+350
=u^2-87u+1862
=(u-38)(u-49)
=(x^2-2x-38)(x^2-2x-49)
1年前
1
