Question

$\begin{array}{l}\text{Inthefollowingexercise,evaluate.}\\ \frac{r-s}{r+s}\text{When}\\ r=10,s=-5\end{array}$

Short answer

$\text{Theresultofevaluatingtheexpressionis}3.$

Step-by-step solution

Step 1. Given information 

$\begin{array}{l}\text{Thegivenexpressionis}\\ \frac{r-s}{r+s}\\ \text{Also,}\\ r=10\text{and}s=-5\\ \text{Wewillevaluatetheexpressionforgivenvaluesof}r\text{and}s.\end{array}$

Step 2. Substitute the value of x and y in the given expression 

$\begin{array}{l}\text{At}r=10\text{and}s=-5,\text{Wehave}\frac{r-s}{r+s}\text{as}\\ \Rightarrow \frac{10-\left(-5\right)}{10+\left(-5\right)}\\ =\frac{10+5}{10-5}\\ =-\frac{15}{5}\\ =\frac{3\times \cancel{5}}{\cancel{5}}\\ =3\end{array}$