SG7

Which of these statements describes a correct method to solve the equation shown below?

x² - 9 = 16

• add 9 on both sides, then square root

• square root both sides, then add 9

• square 16, then add 9

• subtract 9 on both sides, then square root

The total cost of tiling a rectangular patio involves the cost of tiles and labor charges. The length of the patio is 5 feet more than its width, x. If the expression 10x(x + 5) + 300 gives the total cost of tiling, what does 10 represent?

• the labor charges

• the total cost of the tiles

• the area of the patio in square feet

• the cost of the tiles per square foot

Kelsie works at a concert arena. When the price of a ticket is $30, a concert will be attended by 2,500 people. Each time the price is raised by an increment of $5, there will be 100 fewer people at the concert. Kelsie uses the equation R = (30 + 5n)(2500 - 100n) to determine R, the total concert revenue in dollars when there have been n $5 increases in ticket price. Which conclusion is valid?

• The total concert revenue decreases when the price of a ticket is greater than $30.

• The number of people attending the concert is represented by 2500 - 100n.

• The number of times the price is raised is represented by 30 + 5n.

• The cost per concert ticket must be less than $55.

The function rule A = (pi)r² is a model for the area A of a circle with a radius r. Which of the following represents this equation written in function notation?

• A

• B

• C

• D

• 
• 
• 
• 

• (0, -4) and (0, 0)

• (0, 0)

• (-2, 4)

• (0, 4) and (0, 0)

What is the average rate of change of the function f(x) = 2x² + 4 over the interval [–4, –1]?

• -3

• -4

• -6

• -10

Which of the following functions describes a graph that will intersect the x-axis in exactly one point?

• A

• B

• C

• D

Which expression is equal to y, if (x² -1) + y = (2x² + 5)?

• A

• B

• C

• D

A company produces suitcases. There are manufacturing and wholesale costs to produce the suitcases.

The manufacturing costs are modeled by the function f(x) = 2x² – 3x + 4. The wholesale costs are modeled by the function g(x) = x² – 2x + 3. The income that the company receives from selling x suitcases is modeled by the function h(x) = 4x² – 2x.

Which function models the profit, p(x), the company makes from selling x suitcases?

• A

• B

• C

• D