×27-![]() | ÷(1- )×![]() | 9 ×4.25+4 ×![]() | (6 -3 )÷(13+11 ) |
×27-
=(27-1)×
,=26×
,=18;
(2)
÷(1-
)×
=
÷
×
,=
;(3)9
×4.25+4
×
=9
×4.25+4.25×
,=(9
+
)×4.25,=10×4.25,
=42.5;
(4)(6
-3
)÷(13+11
)=
÷
,=
.分析:算式(1)(3)可根据乘法分配律进行计算;
算式(2)(4)可根据四则混合运算的计算运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的.
点评:完成有关于分数的四则混合运算要细心,注意通分约分.