Jason is planning to increase the size of the swimming pool in his backyard. the original swimming pool has a length of 18 feet and a width of 12 feet. the new swimming pool will be 3x feet longer and x feet wider than the original swimming pool. which of the following functions will give the surface area of the new swimming pool in square feet? a. f(x) = 3x2 + 66x + 216 b. f(x) = 3x2 + 54x + 216 c. f(x) = 3x2 + 216 d. f(x) = 3x2 + 30x + 216

answer: c, the green line

step-by-step explanation:

there is no black line, eliminate b.

simple interest implies periodic payments, but the red line shows no payments, eliminate d.

simple interest has equal payments. if paid say every day, the graph is about a straight line (actually a stairstep).

the yellow line is not straight, eliminate a.

check: the green line is straight, answer is c.

simple interest with positive interest rate gives a straight line sloping up to the right. green line:

g(t) = $100 + ($200-$100) ÷ (20 years) × (t years)

= $100 + (4%/year) × ($100)(t years)

incidentally, the yellow line curving upward represents continuously compounded interest

y = $100 × 2^(t years / (14 assuming the yellow line hits $200 at 14 years. 2^0 is 1, so y(0) = $100; 2^(14/14) is 2, so y(14) = $200.

step-by-step explanation:

the true ones are a b and d