Question

How do you solve `y=x+4`, `y=-2x+1` by graphing?

Answer 1

See a solution process below:

Explanation:

First graph the equation `y = x + 4` by plotting two points on the line and then drawing a line through the two points:

Graph Equation 1:

First graph the equation `y = x + 4` by plotting two points on the line and then drawing a line through the two points:

For `x = 0`; `y = 0 + 4 = 4` or `(0, 4)`

For `x = 4`: `y = 4 + 4 = 8` or `(4, 8)`

graph{(x^2+(y-4)^2-0.125)((x-4)^2+(y-8)^2-0.125)(y-x-4)=0 [-20, 20, -10, 10]}

Graph Equation 2:

We do the same for the second equation:

For `x = 0`: `y = (-2 * 0) + 1 = 0 + 1 = 1` or `(0, 1)`

For `x = -3`: `y = (-2 * -3) + 1 = 6 + 1 = 7` or `(-3, 7)`

graph{((x+3)^2+(y-7)^2-0.125)(y+2x-1)(x^2+(y-1)^2- 0.125)(x^2+(y-4)^2-0.125)((x-4)^2+(y-8)^2-0.125)(y-x-4)=0 [-20, 20, -10, 10]}

The two lines intersect at: `(-1, 3)`

graph{((x+1)^2+(y-3)^2-0.075)(y+2x-1)(y-x-4)=0 [-10, 10, -5, 5]}