-9 + 5c + 18 - c = 37
4c + 9 = 37
4c = 37 - 9
4c = 28
4c/4 = 28/4
c = 7
hope this helps
Answer:
I cant help unless i have workable units (0.5) is not a point
but im guessing that you were trying to say (0,5) in which case its
7.07106781187
its a triangle
5 on one side
5 on the other
solve for the hypotenuse
hypotenuse = 
hypotenuse = 7.07106781187
I hope this helps!
They bought 5 trophies total
1st trophy cost $37.50
($18.50+$12.50+$4+$2.50=$37.50)
Each additional trophy cost $15
($12.50+$2.50=$15)
They spent $97.50 total
$97.50-$37.50=$60
Additional trophies $15
$15*X=$60
4 trophies=$60+$37.50 for 1st trophy
$60+$37.50=$97.50
K=8k+28
subtract 8k from both side
-7k = 28
divide both side by -7
k= -4