Question

Answer 1

a) \(=\dfrac{7}{4}-\dfrac{3}{5}=\dfrac{35-12}{20}=\dfrac{23}{20}\)

b) \(=2021-\left(\dfrac{1}{3}.3\right)^2=2021-1^2=2020\)

c) \(=\dfrac{15}{2}.\left(-\dfrac{3}{5}\right)=-\dfrac{9}{2}\)

d) \(=\left(-\dfrac{1}{4}\right)^2\left(\dfrac{4}{11}+\dfrac{7}{11}\right)=\dfrac{1}{16}.1=\dfrac{1}{16}\)

Answer 2

a)\(\dfrac{7}{4}+\dfrac{-3}{5}=\dfrac{7\cdot5+\left(-3\right)\cdot4}{4\cdot5}=\dfrac{23}{20}\)

b) \(2021-\left(\dfrac{1}{3}\right)^2\cdot3^2=2021-\left(\dfrac{1}{3}\cdot3\right)^2=2021-1^2=2020\)

c) \(7,5\cdot\left(-\dfrac{3}{5}\right)=\dfrac{15}{2}\cdot\left(-\dfrac{3}{5}\right)=\dfrac{-3\cdot3}{2}=-\dfrac{9}{2}\)

d) \(\left(-\dfrac{1}{4}\right)^2\cdot\dfrac{4}{11}+\dfrac{7}{11}\cdot\left(-\dfrac{1}{4}\right)^2\)

    \(=\left(-\dfrac{1}{4}\right)^2\cdot\left(\dfrac{4}{11}+\dfrac{7}{11}\right)=\left(-\dfrac{1}{4}\right)^2\cdot1=\dfrac{1}{16}\)