Answer:
(6,21)
Step-by-step explanation:
There are two ways to solve a system of equations: mathematically by substitution, or by graphing.
Math Substitution:
y = x + 15
y = 7x - 21
Since both expression are equal to the same number, set them equal to each other:
x + 15 = 7x - 21
6x = 36
x = 6
Then use x = 6 in either equation to find y:
y = x + 15
y = 6 + 15
y = 21
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Graphically:
Graph both equations and find the solution for x and y where they intersect. See attachment. Intersection at (6,21)
