解方程.①30%x+45%x=3 ②(1+10%)x=1.32 ③12-25%x=1

解方程.①30%x+45%x=3 ②(1+10%)x=1.32 ③12-25%x=10 ④x÷25=15.
2025-06-27 09:01:47
推荐回答(1个)
回答1:

①30%x+45%x=3,
   (30%+45%)x=3,
          0.75x=3,
    0.75x÷0.75=3÷0.75,
              x=4;

②(1+10%)x=1.32,
        1.1x=1.32,
   1.1x÷1.1=1.32÷1.1,
           x=1.2;

③12-25%x=10,
12-0.25x+0.25x=10+0.25x,
      10+0.25x=12,
   10+0.25x-10=12-10,
         0.25x=2,
   0.25x÷0.25=2÷0.25,
             x=8;

④x÷25=

1
5

x÷25×25=
1
5
×25,
        x=5.