(x-5)的平方-17(x-5)+30=0因式分解法,
问题描述:
(x-5)的平方-17(x-5)+30=0因式分解法,
答
(x-5)^2-17(x-5)+30=0
((x-5)-15)((x-5)-2)=0
(x-20)(x-7)=0
故x=20或x=7