Solving a system of equations using elimination

Use the elimination method to solve the system of equations.
x + y = 7
2x + y = 11

x + y = 7   
2x + y = 11
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-x = -4   {subtracted the two equations, eliminating the y}
x = 4   {divided each side by -1}

x + y = 7   {top original equation}
4 + y = 7   {substituted 4, in for x, into top original equation}
y = 3   {subtracted 4 from each side}

x = 4 and y = 3

(4,3) is the solution to the system of equation.  This means the coordinates (4,3) are where the two lines intersect, when graphed, as shown below.

- Algebra House