脱式计算(能用简便方法计算的要用简便方法). 17.5-4.25-5.75 1.68÷(2.4×2-4.6) 9/36÷[3/4-(7/16-1/4)].

问题描述:

脱式计算(能用简便方法计算的要用简便方法).
17.5-4.25-5.75
1.68÷(2.4×2-4.6)

9
36
÷[
3
4
-(
7
16
-
1
4
)].

(1)17.5-4.25-5.75
=17.5-(4.25+5.75)
=17.5-10
=7.5;
(2)1.68÷(2.4×2-4.6)
=1.68÷(4.8-4.6)
=1.68÷0.2
=8.4;
(3)

9
36
÷[
3
4
-(
7
16
-
1
4
)]
=
9
36
÷[
3
4
3
16
]

=
9
36
÷
9
16

=
9
36
×
16
9

=
4
9