1. desmond wants to sell his car that he paid $8,000 for 2 years ago. the car depreciated, or decreased in value, at a constant rate each month over a 2-year period. if x represents the monthly depreciation amount, which expression shows how much desmond can sell his car for today? a.8,000 + 24x b.8,000 − 24x c.8,000 + 2x d.8,000 − 2x 2. avi and sergi are saving money to buy a game system. avi has $2 more than double the amount of money sergi has. together, they have $40. write an equation to determine how much money sergi and avi have together. a. x + 2x + 2 = 40 b.2x + 2 = 40 c. x + 2x − 2 = 40 d.2x − 2 = 40 isabella solved the following equation: 4x − 2x + 8 = 6(x + 4) step work justification 1 4x − 2x + 8 = 6x + 24 distributive property 2 2x + 8 = 6x + 24 combine like terms 3 −4x + 8 = 24 addition property of equality 4 −4x = 16 subtraction property of equality 5 x = −4 division property of equality which step has an incorrect justification? a. step 1 b. step 2 c. step 3 d. step 4

1. C. 8000 - 24x; 2 A. x + 2x + 2 = 40; 3. C. Step 3

Step-by-step explanation

1. Desmond  

2. Avi and Sergi  

3. Isabella  

Step 3 has the incorrect justification. Isabella subtracted 6x from each side, so she should have used the Subtraction Property of Equality

a is the right answer

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.