A is at -8 and C i5 at 5
-8 to 0 is 8 units and 0 to 5 is 5 units.
8 +5 = 13
AC is 13 units long.
y = -2/3x - 4
simply plug into y = mx+b where m is slope and b is y intercept
(2/3)*(c-18)=7 <em>(Multiply terms on both sides of equation by 3)</em>
2(c-18)=21
2c-36=21
2c=57
c=57/2
c=28.5