Question

若AB=0则A=0或B=0 因为2x^2-3x-2=(2x+1)(x-2),故,当x=-0.5或2时,代数式2x^2-3

Answer 1

设3x^2-kx-5k+1=(x+1)(3x+m)＝3x^2+3x+mx+m=3x^2+(3+m)x+m,则

3+m=-k

-5k+1=m

从而,3-5k+1=-k,k=1