x²-(2k+3)x+k²+3k+2=0这方程怎么解?
问题描述:
x²-(2k+3)x+k²+3k+2=0这方程怎么解?
答
x²-(2k+3)x+k²+3k+2=0
→x²-[(k+1)+(k+2)]x+(k+1)(k+2)=0
→[x-(k+1)][x-(k+2)]=0
∴x1=k+1, x2=k+2.