what i need answered

Question

Solve the system: -3x + y = 7 and 5x + 2y = 3 Write your answer as a coordinate point. 

Answer 1

-3x + y = 7

5x + 2y = 3

These sure confused me when I first learned them! What I would do is solve the 1st equation for y.

y = 3x + 7

Now, remember that "=" means just that. One side is the same as the other. This means we can substitute one side for the other.

5x + 2(3x + 7) = 3

5x + 6x + 14 = 3

11x = -11

x = -1

y = 3(-1) + 7

y = -3 + 7

y = 4

(-1,4) is the point where our two graphs meet, thus being the one point on BOTH lines. It is therefore the solution to our system of equations.