Depends on if you want it rounded.
14.47
Answer:
To solve a system of linear equations graphically we graph both equations in the same coordinate system. The solution to the system will be in the point where the two lines intersect. The two lines intersect in (-3, -4) which is the solution to this system of equations. I hope this helped!
The first equation tells you that 
. If you substitute this expression for 
in the second, we have
And we can deduce 
Make y = mx = b
y = -x - 1
Slope is -1
Perpendicular = opposite sign and reciprocal slope
1/1 = 1, slope would be 1
Solution: slope = 1
