Question

Thực hiện phép tính hợp lí:

a) (9/25-2.18) : (19/5+0.2)

Answer 1

\(\left(\dfrac{9}{25}-2.8\right):\left(\dfrac{19}{5}+0.2\right)\)

\(=\left(\dfrac{9}{25}-\dfrac{14}{5}\right):\left(\dfrac{19}{5}+\dfrac{1}{5}\right)\)

\(=\left(\dfrac{9-70}{25}\right):4\)

\(=\dfrac{-61}{25}:4=\dfrac{-61}{25}.\dfrac{1}{4}\)

\(=-\dfrac{61}{100}\)

Answer 2

\(\left(\dfrac{9}{25}-2.18\right):\left(\dfrac{19}{5}+0,2\right)\)

\(=\left(\dfrac{9}{25}-36\right):\left(\dfrac{19}{5}+0,2\right)\)

\(=\dfrac{-891}{25}:4=\dfrac{-891}{100}\)