100x(X—5)=80x(X—1)解方程

问题描述:

100x(X—5)=80x(X—1)解方程

100x(X—5)=80x(X—1)
100x²-500x=80x²-80x
20x²-420x=0
x²-21x=0
x(x-21)=0
x=0或x=21