Bài 3 :
\(a,\left(\frac{2}{5}\right)^2+5\frac{1}{2}:\left(4,5-2\right)+\frac{2^3}{\left(-4\right)}\)
\(=\frac{4}{25}+\frac{11}{2}:\frac{5}{2}+\frac{8}{\left(-4\right)}\)
\(=\frac{4}{25}+\frac{11}{5}-2\)
\(=\frac{59}{25}-2\)
\(=\frac{9}{25}\)
b, Giống câu a
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