# pre-calculus-midterm-math-homework-help

Name: _________________________

3.

Solve the system by the substitution method. Show your work.

2y – x 5

x2 + y2 – 25 0

4.

Graph the function. Then use your graph to find the indicated limit. You do not have to provide the graph

 f(x) 5x – 3,lim /x—>5 f(x)

5.

Use Gaussian elimination to find the complete solution to the system of equations, or state that none exists. Show your work.

4x – y + 3z 12

x + 4y + 6z -32

5x + 3y + 9z 20

6.

Solve the system of equations using matrices. Use Gaussian elimination with back-substitution.

x + y + z -5

x – y + 3z -1

4x + y + z -2

7. A woman works out by running and swimming. When she runs, she burns 7 calories per minute. When she swims, she burns 8 calories per minute. She wants to burn at least 336 calories in her workout. Write an inequality that describes the situation. Let x represent the number of minutes running and y the number of minutes swimming. Because x and y must be positive, limit the boarders to quadrant I only.