Question

Solve the following system of linear equations by choosing either substitution or elimination. You must show all work to receive credit.

Answer 1

To solve the system of equations given, we shall use the elimination method

`\begin{gathered} -2x-5y=11---(1) \\ 3x+5y=-4---(2) \\ \text{Add equation (1) to equation (2)} \\ (-2x+3x)+(-5y+5y)=11+\lbrack-4\rbrack \\ x+0=7 \\ x=7 \\ \text{Substitute for the value of x into equation (1)} \\ -2x-5y=11 \\ -2(7)-5y=11 \\ -14-5y=11 \\ Add\text{ 14 to both sides of the equation} \\ -5y=25 \\ \text{Divide both sides by -5} \\ (-5y)/(-5)=(25)/(-5) \\ y=-5 \\ \text{The answer is} \\ x=7,y=-5 \end{gathered}`

The answer is

x= 7 and y = -5