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
答
(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