Question

Thực hiện phép tính biết:

a) \(\dfrac{2}{3}:\dfrac{-5}{3}+\dfrac{7}{5}\)

b) \(3^7:3^5+\left|-2\right|.5^2\)

Answer 1

a,

\(\dfrac{2}{3}:\dfrac{-5}{3}+\dfrac{7}{5}=\dfrac{2}{3}\cdot\dfrac{-3}{5}+\dfrac{7}{5}=-\dfrac{2}{5}+\dfrac{7}{5}=\dfrac{5}{5}=1\)

b,

\(3^7:3^5+\left|-2\right|\cdot5^2=3^2+2\cdot25=9+50=59\)

Answer 2

a) \(\dfrac{2}{3}:\dfrac{-5}{3}+\dfrac{7}{5}\)

\(=\dfrac{2}{3}.\dfrac{3}{-5}+\dfrac{7}{5}\)

\(=\dfrac{-2}{5}+\dfrac{7}{5}\)

\(=\dfrac{5}{5}=1\)

b) \(3^7:3^5+\left|-2\right|.5^2\)

\(=3^{7-5}+2.25\)

\(=3^2+50\)

\(=59\)

Answer 3

\(\dfrac{2}{3}:\dfrac{-5}{3}+\dfrac{7}{5}\\ =\dfrac{2}{3}.\dfrac{-3}{5}+\dfrac{7}{5}\\ =-\dfrac{2}{5}+\dfrac{7}{5}=\dfrac{5}{5}=1\)

b.

\(3^7:3^5+\left|-2\right|.5^2\\ =3^2+2.25\\ =9+50=59\)