The johnsons want to cover their backyard with new grass. their backyard is rectangular, with a length of 3x – 5 feet and a width of 4x – 10 feet. however, their rectangular swimming pool, along with its surrounding patio, has dimensions of x + 8 by x – 2 feet. what is the area of the region of the yard that they want to cover with new grass? 6x2 – 55x + 104 ft2 x2 + 6x – 16 ft2 11x2 – 56x + 66 ft2 12x2 – 50x + 50 ft2

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.