第52页 - 亮点给力提优课时作业本七年级数学江苏版

D

$10$

$154000$

$解:原式=1\frac{1}{2}-1\frac{1}{4}+3\frac{3}{4}－\frac{1}{4}-3\frac{3}{4}-4\frac{1}{2}$

$=(1\frac{1}{2}-4\frac{1}{2})-(1\frac{1}{4}+\frac{1}{4})+(3\frac{3}{4}-3\frac{3}{4})$

$=-3-1\frac{1}{2}$

$=-4\frac{1}{2}$

$ \begin{aligned}解：原式&=(－1\frac{1}{3}+3\frac{2}{3}-2\frac{1}{3})+(29\frac{3}{5}－14\frac{2}{5})+( 15\frac{1}{4}+\frac{1}{4}) \\ &=0+15\frac{1}{5}－15 \\ &=\frac{1}{5} \\ \end{aligned}$

$解：由题意，得a=\frac{2022×(2022-1)}{2021×(2021+1)}$

$=\frac{2022×2021}{2021×2022}$

$=1$

$同理可得b=1,c=1,所以abc=1$

$解：原式=(－\frac{3}{4})³×0.75+0.25×(-\frac{3}{4})³-1× (－\frac{3}{4})³+64×(-\frac{3}{4})³$

$=(－\frac{3}{4})³×(0.75+0.25-1+64)$

$=-\frac{27}{64}×64$

$=-27$

$ 解：原式=[16+1.63×(2.87+9.63)－125×0.115]÷0.11$

$=[16+(1.63×12.5一12.5×1.15)]÷0.11$

$=[16+(1.63－1.15)×12.5]÷0.11$

$=(16+0.48×12.5)÷0.11$

$=[16+6×(0.08×12.5)]÷0.11$

$=22÷0.11$

$=200$