脱式计算(能简便计算的要简便计算) 3×( 1 3 - 1 5 )×5

2025-03-05 11:02:39
推荐回答(1个)
回答1:

①3×(
1
3
-
1
5
)×5,
=3×
1
3
×5-3×
1
5
×5,
=5-3,
=2;

②(
1
8
+
3
4
)×
1
7
+3,
=
7
8
×
1
7
+3,
=
1
8
+3,
=3
1
8


③75×
1
4
+25×25%,
=75×0.25+25×0.25,
=(75+25)×0.25,
=100×0.25,
=25;

4
7
×15-
4
7

=
4
7
×(15-1),
=
4
7
×14,
=8.