for part B
the fixed cost is 500 dollars because it is a set inital amount, the varibale cost is .15 because it is the cost dependent on something else (per indicated variable part)
y=.15x+500
.15 cents per flyer, add 500 because that is the set amount it costs to even create the flyer
Plug in 500 for the equation
y=.15(500)+500
y=75+500
y=575
for part a b=ka for direct variations so the direct one is C - two items directly multiplied y=mx+b for partial variation so its A,D - basically the equation of a line A is neither - shows neither of these relationships