(50-40+X)(500-10X)=8000怎么算
问题描述:
(50-40+X)(500-10X)=8000怎么算
答
(50-40+X)(500-10X)=8000 10
答
(50-40+X)(500-10X)=8000
-10 (-30 + x) (-10 + x) == 0
x=30
x=10