Answer:
D
Step-by-step explanation:
u dont really need a calculator for this problem
to find the answer, you have to look at the equation.
f(x)=20x+4
the 4 is the y-intercept (0,4), which tells us that the range will start from number 4.
the 20x tells u to multiply the x by the 20
so if it was 20(1)=20, 20(2)= 40, 20(3)= 60 ....
so if you add x amount of plates to the barbell, it will be 20 times x plus 4(because 4lbs is the weight of the barbell itself)
so 0 plates is 4, 1 plate is 20(2) + 4 = 44, 20(4)+4= 84 ....
(i didnt do 20(1) or 20(3) because you need to have a even number of plates of each side of the barbell.)