Let's say that s=spoons and f=forks.
According to this, we can say that:
{4s+3f=15
{4s+f=13
This is a system.
We can then use elimination to solve and isolate the variable:
(4s-3f=15)
- (4s+f=13)
We can then subtract and conclude that:
-4f=2
-f=1/2
f=-1/2
