Answer:
8 sets of neon markers and 7 sets of metallic markers
Explanation:
Let x represent the number of sets of neon markers. These cost $3 each; this gives us 3x.
Since there are 15 total sets of markers bought, this means there are 15-x sets of metallic markers. Each of these are $4; this gives us 4(15-x).
Together the cost was $52; this gives us the equation
3x+4(15-x) = 52
Using the distributive property,
3x+4(15)+4(-x) = 52
3x+60-4x = 52
-1x+60 = 52
Subtract 60 from each side:
-1x+60-60 = 52-60
-1x = -8
Divide both sides by -1:
-1x/-1 = -8/-1
x = 8
There were 8 sets of neon markers. This means there are 15-8 = 7 sets of metallic markers.