Question

Shelby, Allen, and Denise printed their digital photos. Each requested the same size prints. Shelby paid $2.70 for 5 prints. Allen paid $3.24 for 11 prints. Denise paid $4.05 for 20 prints

Answer 1

Person: Number of prints Total Cost
Shelby 5 2.70
Allen 11 3.24
Denise 20 4.05

To solve for the variable cost:
11 - 5 = 6
3.24 - 2.70 = 0.54
0.54 / 6 = 0.09 per print

To solve for the fixed cost
0.09 x 5 = 0.45
2.70 - 0.45 = 2.25

y = 2.25 + 0.09x

y = 2.25 + 0.09(5) = 2.25 + 0.45 = 2.70
y = 2.25 + 0.09(11) = 2.25 + 0.99 = 3.24
y = 2.25 + 0.09(20) = 2.25 + 1.8 = 4.05

Answer 2

wrote the ordered pairs (5, 2.70), (11, 3.24), and (20, 4.05)

used two of the ordered pairs to find the slope

wrote the point-slope form for a linear equation

substituted the slope and the coordinates of one of the points to write the equation of the line

Explanation: