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

Aug 13, 2017

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 $\left(0 , 4\right)$

For $x = 4$: $y = 4 + 4 = 8$ or $\left(4 , 8\right)$

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 $x = 0$: $y = \left(- 2 \cdot 0\right) + 1 = 0 + 1 = 1$ or $\left(0 , 1\right)$

For $x = - 3$: $y = \left(- 2 \cdot - 3\right) + 1 = 6 + 1 = 7$ or $\left(- 3 , 7\right)$

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: $\left(- 1 , 3\right)$

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