(50-40+X)(500-10X)=8000怎么算

问题描述:

(50-40+X)(500-10X)=8000怎么算

(50-40+X)(500-10X)=8000 10

(50-40+X)(500-10X)=8000
-10 (-30 + x) (-10 + x) == 0
x=30
x=10