Chapter 6.2, Problem 1BGP

To determine

To find: Values of x and y .

Answer to Problem 1BGP

  $\begin{array}{l}x=-3\\ y=1\end{array}$

Explanation of Solution

Given information:

  $2x+5y=-1$ ,

  $y=3x+10$

  $2x+5y=-1$ -----(1)

  $y=3x+10$ ------(2)

Substitute the value of y from equation-(2) in equation-(1)

We get

  $\begin{array}{l}2x+5y=-1\\ \Rightarrow 2x+5\left(3x+10\right)=-1\\ \Rightarrow 2x+5\left(3x\right)+5\left(10\right)=-1\\ \Rightarrow 2x+15x+50=-1\\ \Rightarrow 17x=-1-50\\ \Rightarrow 17x=-51\\ \Rightarrow x=\frac{-51}{17}\\ \Rightarrow x=-3\end{array}$

Substitute value of x in equation-(1)

We get

  $\begin{array}{l}2x+5y=-1\\ \Rightarrow 2\left(-3\right)+5y=-1\\ \Rightarrow -6+5y=-1\\ \Rightarrow 5y=-1+6\\ \Rightarrow 5y=5\\ \Rightarrow y=1\end{array}$

Therefore values of x and y are

  $\begin{array}{l}x=-3\\ y=1\end{array}$