神机妙算:(能简算的要写出简算过程)(1)(14-17)×28+447×7-347×7(2)18×78+0.5×1.25-730÷80+24×5143+51×1943(3)[22.5+(335+1.8-1.21×511)]÷40%(4)[47-(18.75-1÷815)×2]÷0-数学
4 |
7 |
4 |
7 |
=7-4+1×7,
=3+7,
=10;
(2)
1 |
8 |
51 |
43 |
19 |
43 |
=0.125×78+5×0.125-73×0.125+51×
24 |
43 |
19 |
43 |
=(78+5-73)×0.125+51×(
24 |
43 |
19 |
43 |
=10×0.125+51×1,
=1.25+51,
=52.25;
(3)[22.5+(3
3 |
5 |
5 |
11 |
=[22.5+(3
3 |
5 |
=[22.5+(5.4-0.55)]÷40%,
=[22.5+4.85]÷40%,
=27.35÷40%,
=68.375;
(4)[47-(18.75-1÷
8 |
15 |
=[47-(18.75-1.875)×2]÷0.46,
=[47-16.875×2]÷0.46,
=[47-33.75]÷0.46,
=13.25÷0.46,
=28
37 |
46 |
(5)(0.7×
2 |
3 |
5 |
6 |
3 |
2 |
4 |
3 |
5 |
6 |
3 |
4 |
=(
7 |
15 |
11 |
120 |