题目内容
求未知数X
(1)
=
(2)6×3-1.8X=7.2.
(1)
| 10 |
| X |
| 2.5 |
| 0.8 |
(2)6×3-1.8X=7.2.
(1)
=
,
2.5x=10×0.8,
2.5x÷2.5=8÷2.5,
x=3.2;
(2)6×3-1.8X=7.2,
18-1.8X=7.2,
18-1.8X+1.8X=7.2+1.8X,
7.2+1.8X=18,
7.2+1.8X-7.2=18-7.2,
1.8X=10.8,
1.8X÷1.8=10.8÷1.8,
X=6.
| 10 |
| x |
| 2.5 |
| 0.8 |
2.5x=10×0.8,
2.5x÷2.5=8÷2.5,
x=3.2;
(2)6×3-1.8X=7.2,
18-1.8X=7.2,
18-1.8X+1.8X=7.2+1.8X,
7.2+1.8X=18,
7.2+1.8X-7.2=18-7.2,
1.8X=10.8,
1.8X÷1.8=10.8÷1.8,
X=6.
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