4/7*X+100):(3/7*X-100)=2/5

问题描述:

4/7*X+100):(3/7*X-100)=2/5

(4/7*X+100):(3/7*X-100)=2/5
2*(3/7*x-100)=5*(4/7*x+100)
6/7x-200=20/7x+500
20/7x-6/7x=-200-500
2x=-700
x=-350