(1)(613×1.7+713×1.7)÷1710(2)1998÷199819981999(3)6.8×825+0.32×4.2-8÷25(4)12×4+14×6+16×8+…+148×50.-数学
题文
(1)(
(2)1998÷1998
(3)6.8×
(4)
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答案
(1)(
=(
=1×1.7÷
=1.7÷
=1; (2)1998÷1998
=1998÷
=1998÷
=1998÷
=1998×
=
(3)6.8×
=6.8×0.32+0.32×4.2-0.32, =(6.8+4.2-1)×0.32, =10×0.32, =3.2; (4)
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