How do you solve the system #3x+2y=-12# and #x-2y=4# by graphing?
1 Answer
Sep 21, 2016
(-2,-3)
Explanation:
Create a table of values for each equation. (Try using x=0 and then y=0)
{3x + 2y = -12}
Let x = 0. So 2y = -12, and y = -6 --> (0, -6)
Let y = 0. So 3x = -12, and x = -4 --> (-4, 0)
{x - 2y = 4}
Let x = 0. So -2y = 4, and y = -2 --> (0, -2)
Let y = 0. So x = 4 --> (-4, 0)
Plot both lines on a graph. They intersect at (-2, -3). This is the answer. Check by substituting it into both original formulas.
{(3 x -2) + (2 x -3) = -6 + -6 = -12}
{(-2) + (-2 x -3) = -2 + 6 = 4} True
