问题
解答题
|
答案
(1)15×[120-(42+36)]
=15×[120-78]
=15×42
=630;
(2)55×25-25×45
=(55-45)×25
=10×25
=250;
(3)425+21×(12+28)
=425+21×40
=425+840
=1265.
|
(1)15×[120-(42+36)]
=15×[120-78]
=15×42
=630;
(2)55×25-25×45
=(55-45)×25
=10×25
=250;
(3)425+21×(12+28)
=425+21×40
=425+840
=1265.