Martina rents a room in her home to guests. She charges a $25 flat fee per night for
one person. Additional guests are welcome to stay, but she charges $10 per person.
She expects guests to check out by 10 a. m. and charges an extra $5 per hour for late
checkouts. Select the linear equation that correctly represents how much Martina
collects for one night of stay in her home.
A)c= 25 + 10p+ 5h
B) c= 25 + 10 + 5
C) c= 25 - 10p - 5h
D) c+ 25 = 10p+5h

b) well because you get well

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.