解方程 0.8x-0.4=1.2 &n...

解方程 0.8x-0.4=1.2 x-25%x=36 79x+x=4.
2025-02-27 02:35:30
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回答1:


(1)0.8x-0.4=1.2,
 0.8x-0.4+0.4=1.2+0.4,
         0.8x=1.6,
    0.8x÷0.8=1.6÷0.8,
            x=2;

(2)x-25%x=36,
      0.75x=36,
0.75x÷0.75=36÷0.75,
          x=48;

(3)
7
9
x+x=4,
     
16
9
x=4,
 
16
9
16
9
=4÷
16
9

         x=
9
4