SAT Prep Linear Function Quiz

To edit a manuscript, Miguel charges $50 for the first 2 hours and $20 per hour after the first 2 hours. Which of the following expresses the amount, C, in dollars, Miguel charges if it takes him x hours to edit a manuscript, where x > 2?

• C = 20x

• C = 20x + 10

• C = 20x + 50

• C = 20x + 90

A builder uses the function g defined by g (x) = 80x + 10,000 to estimate the cost g(x), in dollars, to build a one-story home of planned floor area of x square feet. If the builder estimates that the cost to build a certain one-story home is $106,000, what is the planned floor area, in square feet, of the home?

• 900

• 700

• 1500

• 1200

In 2014, County X had 783 miles of paved roads. Starting in 2015, the county has been building 8 miles of new paved roads each year. At this rate, in which year will County X first have at least 1,000 miles of paved roads? (Assume that no paved roads go out of service.)

• 2042

• 2028

• 2014

• 2035

Phytoremediation is the use of plant growth to purify pollutants from soil, water, or air. Suppose that a crop of brake ferns can remove 15 milligrams (mg) per square meter of a particular pollutant from the soil in 20 weeks. After 20 weeks, the ferns are harvested and a new crop is planted. If c represents the number of crops of brake ferns needed to phytoremediate soil contaminated with 170 mg per square meter of the pollutant down to healthy levels of 5 mg per square meter, which equation best models the situation?

• 170 - 20c = 5

• 170 + 20c = 5

• 170 - 15c = 5

• 170 + 15c = 5

Felipe is saving money for a class trip. He already has saved $250 that he will put toward the trip. To save more money for the trip, Felipe gets a job where each month he can add $350 to his savings for the trip. Let m be the number of months that Felipe has worked at his new job. If Felipe needs to save $2700 to go on the trip, which equation best models the situation?

• 250m - 350 = 2700

• 250m + 350 = 2700

• 350m - 250 = 2700

• 350m + 250 = 2700