Đáp án:
$24)
a)M=\dfrac{-31}{1000}\\
b)
N=\dfrac{5}{9}\\
c)
P=\dfrac{108}{91}\\
d)
Q=-9$
Giải thích các bước giải:
$24)
a)M=\dfrac{17}{5}.\dfrac{-31}{125}.\dfrac{1}{2}.\dfrac{10}{17}.\dfrac{1}{2^3}\\
=\dfrac{17}{5}.\dfrac{1}{2}.\dfrac{10}{17}.\dfrac{-31}{125}.\dfrac{1}{2^3}\\
=\dfrac{-31}{1000}\\
b)
N=\dfrac{1}{7}.\dfrac{5}{9}+\dfrac{5}{9}.\dfrac{2}{7}+\dfrac{5}{9}.\dfrac{1}{7}+\dfrac{5}{9}.\dfrac{3}{7}\\
=\dfrac{5}{7.9}.(1+2+1+3)\\
=\dfrac{5}{7.9}.7\\
=\dfrac{5}{9}\\
c)
P=\dfrac{6}{7}.\dfrac{8}{13}+\dfrac{6}{9}.\dfrac{9}{7}-\dfrac{3}{13}.\dfrac{6}{7}\\
=\dfrac{6}{7}.\left (\dfrac{8}{13}+\dfrac{9}{9}-\dfrac{3}{13} \right )\\
=\dfrac{6}{7}.\left ( \dfrac{5}{13}+\dfrac{13}{13} \right )\\
=\dfrac{6}{7}.\dfrac{18}{13}\\
=\dfrac{108}{91}\\
d)
Q=\left ( \dfrac{-9}{25} \right ).\dfrac{53}{3}-\left ( \dfrac{-3}{5} \right )^2.\dfrac{22}{3}\\
=\dfrac{-9}{25}.\dfrac{53}{3}-\dfrac{9}{25}.\dfrac{22}{3}\\
=\dfrac{-9}{25}.\left ( \dfrac{53}{3}+\dfrac{22}{3} \right )\\
=\dfrac{-9}{25}.\dfrac{75}{3}\\
=-9$
