Question

1) What number should be added to -4/15 so as to get -5/8 ?

2) What number should be subtracted from 4/5 to get 2/3 ?

Answer 1

$$\begin{gathered} \left(1\right). \\ \mathrm{Let}\mathrm{the}\mathrm{required}\mathrm{number}=x \\ \mathrm{Then}, \\ -\frac{4}{15}+x=-\frac{5}{8} \\ \Rightarrow x=-\frac{5}{8}+\frac{4}{15} \\ \Rightarrow x=\frac{-75+32}{120}=-\frac{43}{120} \\ \left(2\right). \\ \mathrm{Let}\mathrm{the}\mathrm{required}\mathrm{number}=x \\ \mathrm{Then}, \\ \frac{4}{5}-x=\frac{2}{3} \\ \Rightarrow x=\frac{4}{5}-\frac{2}{3} \\ \Rightarrow x=\frac{12-10}{15}=\frac{2}{15} \end{gathered}$$