问题标题:
【用简便方法计算下面各题,再用字母表示出来.(1)18.7-8.8-1.2a-b-c=(2)7.4×9.9+7.4×0.1a×c+b×c=(3)8.9×2.5×4a×b×c(4)16.81+3.51+6.49a+b+c=(5)360÷1.5÷2a÷b÷c=(6)1000÷】
问题描述:
用简便方法计算下面各题,再用字母表示出来.
(1)18.7-8.8-1.2
a-b-c=
(2)7.4×9.9+7.4×0.1
a×c+b×c=
(3)8.9×2.5×4
a×b×c
(4)16.81+3.51+6.49
a+b+c=
(5)360÷1.5÷2
a÷b÷c=
(6)1000÷(125÷1.5)
a÷(b÷c)=
郭南翔回答:
(1)18.7-8.8-1.2
=18.7-(8.8+1.2)
=18.7-10
=8.7;
a-b-c=a-(b+c);
(2)7.4×9.9+7.4×0.1
=(9.9+0.1)×7.4
=10×7.4
=74;
a×c+b×c=(a+b)×c;
(3)8.9×2.5×4
=8.9×(2.5×4)
=8.9×10
=89;
a×b×c=a×(b×c);
(4)16.81+3.51+6.49
=16.81+(3.51+6.49)
=16.81+10
=26.81;
a+b+c=a+(b+c);
(5)360÷1.5÷2
=360÷(1.5×2)
=360÷3
=120;
a÷b÷c=a÷(b×c);
(6)1000÷(125÷1.5)
=1000÷125×1.5
=8×1.5
=12;
a÷(b÷c)=a÷b×c.
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