Answer:
the greatest common multiple of 14 and 21 is 7.
I'm not sure if this is right
py+qy=-4+8
y(p+q)=-4y+8
5y(p+q)=8
5y=8/p+q
64 - (3y + 8y + y) / 40 = 37
Simplify 3y + 8y + y
64 - 12y / 40 = 37
Add 12y / 40 to both sides and subtract 37
27 = 12y / 40
Multiply both sides by 40
1080 = 12y
Divide both sides by 12
90 = y