17.2÷2+2.8×0.5 1.72÷4+2.28×0.25 怎样简便计算
问题描述：
17.2÷2+2.8×0.5 1.72÷4+2.28×0.25 怎样简便计算
答
17.2×1/2+2.8×0.5=(17.2+2.8)×1/2=10
1.72×1/4+2.28×0.25=(1.72+2.28)×1/4=1
答
17×40＝680, 100－63＝37, 3.2＋1.68＝4.88, 2.8×0.4＝ 1.123+25=148 123-35=88 56×7=392 135÷5=27 248+89=337 146-
答
17.2÷2+2.8×0.5
=17.2×0.5+2.8×0.5
=（17.2+2.8）×0.5
=20×0.5
=10
1.72÷4+2.28×0.25
=1.72×0.25+2.28×0.25
=（1.72+2.28）×0.25
=4×0.25
=1