Question

Solve the system of equations.−2x+5y =−217x+2y =15

Answer 1

To solve this question we will use the elimination method.

Adding 7 times the first equation to 2 times the second equation we get:

`14x+4y+(-14x)+35y=30+(-147)\text{.}`

Simplifying the above equation we get:

`4y+35y=-117.`

Solving for y we get:

`\begin{gathered} 39y=-117, \\ y=-(117)/(39), \\ y=-3. \end{gathered}`

Substituting y=-3 in the first equation, and solving for x we get:

`\begin{gathered} -2x+5(-3)=-21, \\ -2x-15=-21, \\ -2x=-6, \\ x=3. \end{gathered}`

Answer:

`\begin{gathered} x=3, \\ y=-3. \end{gathered}`