解方程 30%X+50%X=15 25-10%X=5 90%X-20%=125% 90%X÷23=56 75%÷25%X=20% 60%X-35%X=0.5

2024-11-29 03:17:10
推荐回答(1个)
回答1:

解:(1)30%x+50%x=15,

              80%x=15,

          80%x÷80%=15÷80%,
                  x=
75
4


(2)25-10%x=5,

25-10%x+10%x=5+10%x,

    5+10%x-5=25-5,

   10%x÷10%=20÷10%,

           x=200;


(3)90%X-20%=125%,

 90%X-20%+20%=125%+20%,

    90%X÷90%=145%÷90%,
            x=
29
18



(4)90%X÷
2
3
=
5
6
  90%X÷
2
3
×
2
3
=
5
6
×
2
3

    90%X÷90%=
5
9
÷90%,
            x=
50
81



(5)75%÷25%X=20%,

75%÷25%X×25%x=20%×25%x,

 20%×25%x÷20%=75%÷20%,
      25%x÷25%=
15
4
÷25%,
x=15;

(6)60%X-35%X=0.5,
          25%x=0.5,
     25%x÷25%=0.5÷25%,
             x=2;

(7)(1.5+2.5)X=10,
            4x÷4=10÷4,
                x=
5
2


(8)
2
3
X-
1
2
=
7
5

 
2
3
X-
1
2
+
1
2
=
7
5
+
1
2

    
2
3
x÷
2
3
=
19
10
÷
2
3

         x