(1)42÷15%×
5
7
=280×
5
7
=200
答:这个数是200.
(2)(9-
1
10 ×45)÷
1
2
=(9-4.5)÷
1
2
=4.5×2
=9
答:商是9.
(3)10÷(
1
4 -
1
5 )
=10÷
1
20
=200
答:这个数是200.
(4)48÷(1+20%)
=48÷1.2
=40
答:这个数是40.
(1)42÷15%×
5
7
=280×
5
7
=200
答:这个数是200.
(2)(9-
1
10 ×45)÷
1
2
=(9-4.5)÷
1
2
=4.5×2
=9
答:商是9.
(3)10÷(
1
4 -
1
5 )
=10÷
1
20
=200
答:这个数是200.
(4)48÷(1+20%)
=48÷1.2
=40
答:这个数是40.