#4.

An artist bought a set of 10 paintbrushes that contained x small paintbrushes and y large paintbrushes. The number of small paintbrushes in the set was 4 times the number of large paintbrushes in the set.

Which system of equations can be used to find the numbers of small paintbrushes and large paintbrushes in the set?

x+y=10
x=4y

x-y=10
x=4y

x+y=10
y=4x

x-y=10
y=4x