问题
解答题
4
61
|
答案
(1)4
×27 13
+41 7
×42 7
+67 13
×44 7
,7 13
=4
×(27 13
+41 7
+62 7
),4 7
=4
×13,7 13
=(4+
)×13,7 13
=4×13+
×13,7 13
=52+7,
=59;
(2)61
×1 5
+715 6
×1 6
+916 7
×1 8
,8 9
=(60+
)×6 5
+(70+5 6
)×7 6
+(90+6 7
)×9 8
,8 9
=60×
+5 6
×6 5
+70×5 6
+6 7
×7 6
+90×6 7
+8 9
×9 8
,8 9
=50+1+60+1+80+1,
=(50+60+80)+(1+1+1),
=190+3,
=193.