Question

求未知数i．
（9）

3

7

×

7

9

-i=

9

4

（2）9.2：3

9

2

=i：4

2

3

．

Answer 1

（7）

7

7

×

7

2

-x=

7

4

，
&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp; &n0sp;

7

7

-x=

7

4

，
&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;

7

7

-x+x=

7

4

+x，
&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;

7

7

=

7

4

+x，
&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;

7

7

-

7

4

=

7

4

+x-

7

4

，
&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp; x=

7

7l

；

（l）7.5：7

7

5

=x：4

l

7

，
&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp; 7

7

5

x=7.5×4

l

7

，
&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;7

7

5

x=7，
&n0sp;&n0sp;&n0sp;7

7

5

x÷7

7

5

=7÷7

7

5

，
&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp;&n0sp; x=l

7

76

．