Exam 4: Systems of Linear Equations

You need to spend under $40 each week on breakfast and lunch bought out. Breakfast costs $4 per day and lunch costs $7 per day. Let b be the number of days you buy breakfast out each week and let h be the number of days you buy lunch out each week. Write the inequality described here and graph its solution set.

You need to earn at least $280 each week. You have two part-time jobs: at the coffee shop paying $8.25 per hour and at the student cafeteria paying $7.25 per hour. Let c be the hours you work at the coffee shop each week and let s be the hours that you work at student cafeteria each week. Write the inequality described here.

Graph the solution set of the linear inequality.

Use the graph to determine the solution to the system of equations.

As a first step in solving the system by the method of elimination you add together the two equations. Your resulting equation is . Is this a true statement?

The graph below shows the solution set to an inequality. Is the point in the solution set?

A boat takes a long trip traveling 140 miles downstream in 7 hours. The return trip upstream takes 10 hours. Let b be the rate of the boat in still water in miles per hour and let c be the rate of the current in miles per hour. Determine the two equations of the system described here. Solve the system by the method of substitution. Interpret the solution.

Solve the system of equations using the substitution method.

The mass of bacteria in a Petri dish is 30 micrograms. After 3 hours the bacteria s mass as increased to 141 micrograms. Which one of the following exponential functions model the bacteria s growth where is measured in hours.

Graph the solution set of the linear inequality.

Write the linear inequality for the given graph.

Use the graph to determine the solution to the system of equations.

Determine whether the given point is in the solution set of the system of inequalities graphed below.

Your business making doodads has the following weekly revenue and cost equations. where R represents the weekly revenue in dollars C represents the weekly cost in dollars and d doodads are made and sold. Use the method of substitution to find the break-even point.

You have a total of $7000 in student loan debt from two different semesters. If n of it is debt from the first semester is debt from the second semester.

Solve the system using the elimination method.

Use the table of values to solve the system.

To graph an inequality of the form < a __________ line is used.