\(a.\) \(3\frac{3}{4}+\left(4\frac{2}{4}-3\frac{1}{2}\right):\frac{3}{4}\)
\(=\frac{15}{4}\left(\frac{18}{4}-\frac{7}{2}\right):\frac{3}{4}\)
\(=\frac{15}{4}+\frac{4}{4}:\frac{3}{4}=\frac{15}{4}+\frac{4}{3}\)
\(=\frac{15}{4}+\frac{4}{3}=\frac{61}{12}\)
\(b.\) \(7\cdot\frac{2}{3}-\frac{2}{5}:\frac{1}{2}-\frac{2}{3}\)
\(=\frac{7}{3}-\frac{2}{5}\cdot2-\frac{2}{3}\)
\(=\frac{7}{3}-\frac{4}{5}-\frac{2}{3}=\frac{35-12-10}{15}\)
\(=\frac{13}{15}\)
\(c.\) \(68,7-100:20+70,8\)
\(=68,7-5+70,8\)
\(=63,7+70,8\)
\(=134,5\)
\(d.\)\(\left(5915+445:5\right)-76\cdot25\)
\(=\left(5915+89\right)-1900\)
\(=6004-1900=4104\)
a)=\(\frac{15}{4}+\left(\frac{18}{4}-\frac{7}{2}\right)\)/ \(\frac{3}{4}\)
=\(\left(\frac{33}{4}-\frac{14}{4}\right)\)/ \(\frac{3}{4}\)
= \(\frac{19}{4}\cdot\frac{4}{3}\)
=\(\frac{19}{3}\)
b) = \(\frac{2}{3}\cdot\left(7-1\right)-\frac{2}{5}\cdot\frac{2}{1}\)
= \(\frac{2}{3}\cdot6-\frac{4}{5}\)
= 1-\(\frac{4}{5}\)
= \(\frac{1}{5}\)
c) = 68.7 - 5 + 70.8
= 63.7 + 70.8
=134.5
d) = (5915 - 89) -76*25
= 5826 - 1900
= 3926
XIN LỖI MK LÀM NHẦM CÂU B):
\(b.\)\(7\cdot\frac{2}{3}-\frac{2}{5}:\frac{1}{2}-\frac{2}{3}\)
\(=\frac{14}{3}-\frac{2}{5}\cdot2-\frac{2}{3}\)
\(=\frac{14}{3}-\frac{4}{5}-\frac{2}{3}\)
\(=\frac{70-12-10}{15}=\frac{48}{15}=\frac{16}{5}\)
