Question

Graph the equations to solve the system y= x+4 y= -x-6

Answer 1

You can plot lines by extrapolating two points and connecting them. To extrapolate points on the graph, choose whatever value for x you like, and calculate the correspondent y value.

Line y = x+4:

$\text{choose } x=0 \implies y = 0+4 =4 \implies (0,4) \text{ is on the line}$

$\text{choose } x=1 \implies y = 1+4 =5 \implies (1,5) \text{ is on the line}$

Line y = -x-6:

$\text{choose } x=-3 \implies y = -(-3)-6 =-3 \implies (-3,-3) \text{ is on the line}$

$\text{choose } x=-6 \implies y = -(-6)-6 =0 \implies (-6,0) \text{ is on the line}$

Now draw the first two points (0,4) and (1,5) and connect them. You have the first line. Draw the last two points (-3,-3) and (-6,0) and connect them. You have the second line.

You should find out that the two lines cross at (-5,-1)