153k views
5 votes
Find the solution of this system of equations2x+5y=-49-2x+8y=-68

User AzP
by
8.7k points

1 Answer

2 votes

Given the system of equations :


\begin{gathered} 2x+5y=-49 \\ -2x+8y=-68 \end{gathered}

Add the equations to eliminate x :


\begin{gathered} (2x+5y)+(-2x+8y)=-49+(-68) \\ 2x+5y-2x+8y=-117 \\ (2x-2x)+(5y+8y)=-117 \\ 13y=-117 \end{gathered}

divide both sides by 13 to find the value of y :


\begin{gathered} (13y)/(13)=(-117)/(13) \\ \\ y=-9 \end{gathered}

To find x , substitute with the value of y at the first equation :


\begin{gathered} 2x+5\cdot-9=-49 \\ 2x-45=-49 \\ 2x=-49+45 \\ 2x=-4 \\ \\ x=-(4)/(2) \\ \\ x=-2 \end{gathered}

So, the solution of the system is :


\begin{gathered} x=-2 \\ y=-9 \end{gathered}

The solution can be written as the order pair (x,y):


(x,y)=(-2,-9)

User Ratul
by
8.7k points

Related questions

asked Apr 18, 2023 115k views
Terry Djony asked Apr 18, 2023
by Terry Djony
8.4k points
1 answer
0 votes
115k views
1 answer
3 votes
122k views
1 answer
2 votes
225k views