Question

Solve the below system of equations using the best method. Please describe the method used [substitution, graphing, elimination, etc], and give your answer in the form (x,y).

y = 2x + 3
y = -x - 5

Answer 1

Since both equations are solved for y, use substitution.

y = 2x + 3
y = -x - 5

2x + 3 = -x - 5

3x + 3 = -5

3x = -8

x = -8/3

Now substitute -8/3 in for x in the original first equation, and solve for y.

y = 2x + 3

y = 2(-8/3) + 3

y = -16/3 + 9/3

y = -7/3

Solution: (-8/3, -7/3)