选择合理的方法进行计算.(1)3-14-13-34(2)7.8×1.17-7.8×0.17(3)10-712-512(4)58+45-38+15(5)0.25+1115+34+415(6)715+1921+221.-数学
题文
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答案
(1)3-
=3-(
=3-(
=3-(1+
=3-1
=1
(2)7.8×1.17-7.8×0.17 =7.8×(1.17-0.17), =7.8×1, =7.8; (3)10- |
题文
|
答案
(1)3-
=3-(
=3-(
=3-(1+
=3-1
=1
(2)7.8×1.17-7.8×0.17 =7.8×(1.17-0.17), =7.8×1, =7.8; (3)10- |