解比例: X:40=2.5:4 1 14:X=0.4:8 X:3.5=40.5.

问题描述:

解比例:
X:40=2.5:4 1 
14:X=0.4:8
X:3.5=40.5.

(1)x:40=2.5:4 1,
           41x=40×2.5,
       41x÷41=100÷41,
             x=2

18
41

(2)14:x=0.4:8,
      0.4x=14×8,
 0.4x÷0.4=112÷0.4,
         x=280;
(3)x:3.5=40.5,
          x=3.5×40.5,
          x=141.75.