In the function y = 12.00x + 50, y represents the cost of carpet by the square yard and x represents the number of square yards. how much does the cost increase for square yard of carpet purchased?
a) x
b) $12.00
c) $50.00
d) $62.00

so this is very simple.

if f(x)=12x +50, and we want to know how much the cost goes up per square yard, we look at the relationship.

if the coefficient of x is 12, the cost will go up $12 per square yard.

it is NOT 62 because the 50 is a one time thing that is only added one time. think about it like having the price be $50 at 0 yards. it's almost like a flat fee. for 1 yard its 62, 2 its 74, etc. it goes up 12 each time. additionally, it's not x because x is the amount of yards, not the cost of a yard. it is not 50 because 50 is added, and is not in relationship to x.

so, the answer is b.

hope I helped.