解方程: 30%x+85=70%x+25 x÷(1-24%)=1.15 5x+38+2

解方程: 30%x+85=70%x+25 x÷(1-24%)=1.15 5x+38+2x=23.
2024-12-27 09:02:33
推荐回答(1个)
回答1:

(1)30%x+85=70%x+25,
    30%x+85-30%x=70%x+25-30%x,
           85-25=0.4x+25-25,
         60÷0.4=0.4x÷0.4,
               x=150;

(2)x÷(1-24%)=1.15
x÷(1-24%)×(1-24%)=1.15×(1-24%),
                      x=1.15×0.74,
                      x=0.851;

(3)

5x+3
8+2x
=
2
3

(5x+3)×3=(8+2x)×2,
      15x+9=16+4x,
   15x+9-4x=16+4x-4x,
    11x+9-9=16-9,
    11x÷11=7÷11,
          x=
7
11