Answer:
15
Step-by-step explanation:
The equation is just a plug in and solve. you have your given variables and all you have to do it plug them into the matching spot and solve
R=8 P=7
8+7=15
Discriminant = square root (b^2 -4*a*c)
square root (64 -4*1*12) =
square root (16) =
4
Therefore it has 2 rational soltions
A) K=1/2C-3
K+C=18
Hope this helps! Have a great day :)