X=5
等号两边同乘一个X
1200/X+1200/X×75/100×(X-1)=1200×80/100 等号两边同乘X
1200+1200×75/100×(X-1)=1200X×80/100
1200+900×(x-1)=960X
1200+900X-900=960x
300=60X
x=5
X=5
等号两边同乘一个X
1200/X+1200/X×75/100×(X-1)=1200×80/100 等号两边同乘X
1200+1200×75/100×(X-1)=1200X×80/100
1200+900×(x-1)=960X
1200+900X-900=960x
300=60X
x=5