Answer:
c = about 0.5 pence
r = about 0.12 pence
Explanation:
Here we have a system of equations, so our goal would be to elimate one of the variables. We can use either, but since 24r is a multiple of 6r, it's easier to use.
We'd start by multiplying the second equation by 4:
24r + 36c = 10.08
We can then subtract the two equations:
24r + 15c = 5.88
-
24r + 36c = 10.08
-----------------------------
24r - 24r + 15c - 36c = 5.88 - 10.08
-21c = -9.492
As we can see, the r got eliminated, so now we can solve for c.
c = -9.492/-21
c = 0.452 pence
To get r, we just plug in this value of c to any of the two equations.
6r + 9(0.452) = 2.52
r = about 0.12