问题
解答题
|
答案
(1)1.25×4×0.6×0.8×2.5,
=(1.25×0.8)×(2.5×4)×0.6,
=1×10×0.6,
=6;
(2)
×[25 16
+(2 5
-2 3
)÷2 5
],1 3
=
×[25 16
+(2 5
-2 3
)÷2 5
],1 3
=
×[25 16
+(2 5
-10 15
)×3],6 15
=
×[25 16
+2 5
×3],4 15
=
×[25 16
+2 5
],4 5
=
×5 16
,16 5
=1;
(3)4
+4.2×71 5
+15 7
×42 7
,1 5
=4.2+4.2×7
+15 7
×4.2,2 7
=4.2×(1+7
+15 7
),2 7
=4.2×10,
=42;
(4)3
×11 2
÷(4.5-0.625÷1 5
)÷30%,5 16
=
×7 2
÷(4.5-6 5
×5 8
)×16 5
,10 3
=
÷(4.5-2)×21 5
,10 3
=
×21 5
×2 5
,10 3
=(
×21 5
)×10 3
,2 5
=14×
,2 5
=
,28 5
=5
;3 5
(5)1
:11 5
=X:2 7
,9 14
1
x=12 7
×1 5
,9 14
1
x=2 7
×6 5
,9 14
x×9 7
=7 9
×6 5
×9 14
,7 9
x=
×(6 5
×9 14
),7 9
x=
×6 5
,1 2
x=
;3 5
(6)5×0.36-0.75X=
,3 5
1.8-0.75x=0.6,
0.75x=1.2,
x×3 4
=1.2×4 3
,4 3
x=1.6;