用简便方法计算.1.7+3.98+1504750×515.73-3817+(4.27-2917)45×2.08+1.5×37.699999×77778+33333×66666;362+548×361362×548-18611×4+14×7+17×10+…+197×10012+14+18+11-数学

题文

用简便方法计算.
1.7+3.98+
1
50
47
50
×51
5.73-3
8
17
+(4.27-2
9
17
45×2.08+1.5×37.6
99999×77778+33333×66666
362+548×361
362×548-186
1
1×4
+
1
4×7
+
1
7×10
+…+
1
97×100
1
2
+
1
4
+
1
8
+
1
16
+
1
32
题型:解答题  难度:中档

答案

1.7+3.98+
1
50

=1.7+(3.98+0.02),
=1.7+4,
=5.7;

47
50
×51,
=
47
50
×(50+1),
=
47
50
×50+
47
50
×1,
=47+
47
50

=47
47
50


5.73-3
8
17
+(4.27-2
9
17
),
=5.73+4.27-(3
8
17
+2
9
17
),
=10-6,
=4;

45×2.08+1.5×37.6,
=1.5×62.4+1.5×37.6,
=1.5×(62.4+37.6),
=1.5×100,
=150;

99999×77778+33333×66666,
=99999×77778+33333×(3×22222),
=99999×77778+(33333×3)×22222,
=99999×77778+99999×22222,
=99999×(77778+22222),
=99999×100000,
=9999900000;

362+548×361
362×548-186

=(362+548×361)÷(362×548-186),
=[362+548×(362-1)]÷(362×548-186),
=[362-548+548×362]÷(362×548-186),
=(362×548-186)÷(362×548-186),
=1;