(X-80)(X-20)=80(X+20)
问题描述:
(X-80)(X-20)=80(X+20)
答
x^2-20x-80x+1600=80x+1600
x^2-180x=0
x(x-180)=0
x=0或x=180
答
xx-100x+1600=80x+1600
xx-180x=0
x(x-180)=0
x=0或x-180=0
x=0或x=180
答
x^2-100x+1600-80x-1600=0
x^2-180x=0
x(x-180)=0
x=0
x=180