问题
解答题
|
答案
(1)(
+5 6
-7 8
)÷5 12
,1 24
=(
+5 6
-7 8
)×24,5 12
=
×24+5 6
×24-7 8
×24,5 12
=20+21-10,
=31,
(2)[
=[ =[ = = (3)20.07×1994-19.93×2007, =(20.07×100)×(1994÷100)-19.93×2007, =2007×19.94-19.93×2007, =2007×(19.94-19.93), =2007×0.01, =20.07, (4)2.5×0.875+0.25×1.25, =2.5×0.875+(0.25×10)×(1.25÷10), =2.5×0.875+2.5×0.125, =2.5×(0.875+0.125), =2.5×1, =2.5, (5)999 =(999+ =(1000-1+100-1+10-1)+( =1110-3+3, =1110, (6)2.5- =2.5- =2.5- =2.5-( =2.5-1, =1.5, |