Question

Benito embroiders and sells T-shirts. The graph shows his profit as a function of the number of shirts sold. After selling a certain number of shirts, Benito uses some earnings to buy more materials and then increases the price of the shirts. Which of the following correctly compares the two parts of the function in Part A, over the intervals [0, 7] and [8, 11]? . . Benito made an extra $25 after selling 7 shirts. The price of one shirt increases from $10 to $15. Benito spent $1 after selling 50 shirts Benito's profit per shirt increases from $10 to $15.

Answer 1

Answer:

The correct option is;

Benito's profit per shirt increased from $10 to $15

Step-by-step explanation:

Over the interval [0, 7] from 0 to 7 on the x axis, we have;

At x = 0, y = -20, therefore the y-intercept = -20

At y = 0, x = 2 which is the x-intercept

The slope, m₁ of the straight line plotted dots on the interval from 0 to 7 on the x axis is found as follows;

m  = (y₂ - y₁)/(x₂ - x₁)

m₁ = (0 - (-20))/(2 - 0) = 10

The equation of the interval is therefore;

y - 0 = 10×(x - 2)

y = 10·x - 20

Therefore, the profit, y increases by $10, for each shirt, x, sold over the interval from 0 to 7 on the x axis

Over the interval [8, 11] from 8 to 11 on the x axis, we have;

At x = 9, y = 40,

At x = 11, y = 70

The slope, m₂ of the straight line plotted dots on the interval from 8 to 11 on the x axis is found as follows;

m  = (y₂ - y₁)/(x₂ - x₁)

m₂ = (70 - 40)/(11 - 2) = 15

The equation of the interval is therefore;

y - 70 = 15×(x - 11)

y = 15·x - 165

Therefore, the profit, y increases by $15, for each shirt, x, sold over the interval from 8 to 11 on the x axis.