Question

[nguyen phuong an]

bài thực hiện phép tính

o) 0,25 . 1 3/5 . (-5/4)² : -4/7

n) (3 2/5 - 2 2/5) . ( -5/3) + 3 ( 2 1/2 : 1/2)

Answer 1

[Shinran]

\(0,25.1\frac{3}{5}.\left(\frac{-5}{4}\right)^2:\left(\frac{-4}{7}\right)\)

\(=\frac{1}{4}.\frac{8}{5}.\frac{-5}{4}.\frac{-7}{4}\)

\(=\frac{1.8.\left(-5\right).\left(-7\right)}{4.5.4.4}\)

\(=\frac{280}{320}=\frac{7}{8}\)

\(\left(3\frac{2}{3}-2\frac{2}{5}\right).\left(\frac{-5}{3}\right)+3\left(2\frac{1}{2}:\frac{1}{2}\right)\)

\(=\left(\frac{17}{5}-\frac{12}{5}\right).\frac{-5}{3}+3\left(\frac{5}{2}.\frac{2}{1}\right)\)

\(=\frac{17-12}{5}.\frac{-5}{3}+3\left(\frac{5.2}{2.1}\right)\)

\(=1.\frac{-5}{3}+3.5\)

\(=\frac{-5}{3}+15\)

\(=\frac{-5+45}{3}\)

\(=\frac{40}{3}\)