Đáp án:
d. \(\dfrac{1}{5}\)
Giải thích các bước giải:
\(\begin{array}{l}
a.23\left( {15 + 75 + 10} \right) = 23.100 = 2300\\
c.12\left( {43 + 17} \right) + 12.5.18\\
= 12\left( {60 + 5.18} \right)\\
= 12\left( {60 + 90} \right)\\
= 12.150 = 1800\\
e.\left( {18 + 19} \right)\left( {17 + 12 - 1} \right)\\
= 37.28 = 1036\\
f.\left( {26 + 14} \right)\left( {23 - 1 + 36} \right)\\
= 40.58 = 2320\\
g.\dfrac{{3600}}{{18\left( {13 + 27} \right)}} = \dfrac{{3600}}{{18.40}} = \dfrac{{3600}}{{720}} = 5\\
k.136\left( {143 + 157} \right) + 64\left( {143 + 157} \right)\\
= 136.300 + 64.300 = 300\left( {136 + 64} \right)\\
= 300.200 = 60000\\
m.273\left( {31 + 38} \right) + 727.69\\
= 273.69 + 727.69\\
= 69\left( {273 + 727} \right) = 69.1000 = 69000\\
b.17\left( {36 + 1 + 63} \right) = 17.100 = 1700\\
d.\dfrac{{120}}{{15\left( {13 + 27} \right)}} = \dfrac{{120}}{{15.40}} = \dfrac{3}{{15}} = \dfrac{1}{5}
\end{array}\)
