Question

解方程 7.8×3X=3.6	X÷1.98=0.4	（4.5-X）×0.375=0.75
12X+23X=14	X-0.52X=3.2×0.15	12X+25%=10．

Answer 1

①7.8×3x=3.6
7.8÷3.6×3x=3.6÷3.6
6x=1
6x÷6=1÷6
x=

1

6

②x÷1.98=0.4
x×1.98÷1.98=0.4×1.98
x=0.792

③（4.5-x）×0.375=0.75
4.5×

3

8

-

3

8

x=

3

4

13.5

8

-

3

8

x=

6

8

3

8

x=

7.5

8

3

8

x×

8

3

=

7.5

8

×

8

3

x=2.5

④12 x+23 x=14
35x=14
35x÷35=14÷35
x=

2

5

⑤x-0.52x=3.2×0.15
0.48x=0.48
0.48x÷0.48=0.48÷0.48
x=1

⑥12x+25%=10
12x+0.25=10
12x+0.25-0.25=10-0.25
12x=9.75
12x÷12=9.75÷12
x=0.8125