1/80×x×2+1/80(x+5)×8=3/4 火速
问题描述：
1/80×x×2+1/80(x+5)×8=3/4 火速
答
1/80×x×2+1/80(x+5)×8=3/4
左右两边同时乘以 80
2x+8（x+5）=3×20
2x+8x+40=60
10x=60-40
10x=20
x=2
答
1/80×x×2+1/80(x+5)×8=3/4
1/40×x+1/10(x+5)=3/4
两边乘40
x+4x+20=30
5x=30-20=10
x=10÷5
x=2