# Equations

Find a linear function f(x) = mx + b whose graph has the given slope and y-intercept.

6. Slope: 4/5 ; y-intercept: (0,28)

Find an equation of the line having the given slope and containing the given point

14. m = 3, (-2, -2)

Find an equation of the line containing the given pair of points.

28. (-4, -7) and (-2, -1)

Write an equation of the line containing the given point and parallel to the given line.

36. (-4, -5); 2x + y = -3

Write an equation of the line containing the given point and perpendicular to the given line.

42. (-3, -5); 5x - 2y = 4

True tone Graphics bought a computer for $3800. The value V(t) of the computer depreciates at a rate of $50 per month.

A) Formulate a linear function for the value V(t) of the computer after t months.

B. Graph the model.

C. Use the model to determine the value of the computer after 10 months.

50. The table below shows data regarding the median age of women at first marriage in 1970 and in 2003.

YEAR MEDIAN AGE OF WOMEN AT FIRST MARRIAGE

1970 20.8

2003 25.0

A. Use the two data points to find a linear function that fits the data. Let x= the number of years since 1970 and A = the median age at first marriage x years from 1970.

B. Use the function to predict the median age of women at first marriage in 2008 and in 2015.

Solve the system by the substitution method.

6. m - 2n = 3

4m + n =1

18. The perimeter of a soccer field is 340m. The length exceeds the width by 50m. Find the length and the width.

22. An airplane has a total of 152 seats. The number of coach-class seats is 5 more than six times the number of first-class seats. How many of each type of seat are there on the plane?

8.3

6. solve the system by the elimination method

3x + 2y = 3

9x - 8y = -2

16. 3x - 2y = 1

-6x + 4y = -2

18. 3x - 5y = -2

5y - 3x = 7

#### Solution Summary

This provides several examples of working with equations and creating linear functions.