7th Grade Math

388 Linear Functions

Example 1 Graph the function represented by each table.

1. Total Cost of Baseballs
   Baseball Total Cost ($)
   14
   28
   312
   416
   2. Savings Account
   Week Amount ($)
   0 300
   1 350
   2 400
   3 450

Example 2 Graph each equation.

33 y = x - 1 4. y = - 1 x 5. y = - 2 x + 3

Example 3 6. MEASUREMENT The perimeter of a square is 4 times as great as the length

of any of its sides. The equation p = 4 s describes the perimeter p

of a square with sides s units long. Represent this function by a graph.

= Step-by-Step Solutions begin on page R1.

Extra Practice begins on page EP2.

Example 1 Graph the function represented by each table.

7. Total Phone Bill
   Time (min) Total ($)
   0 10.00
   1 10.08
   2 10.16
   3 10.24
   8. Calories in Fruit Cups
   Servings Total Calories
   1 70
   3 210
   5 350
   7 490

Example 2 Graph each equation.

9. y = x + 1 10. y = x + 3 11. y = x


10. y = - 2 x 13. y = 2 x + 3 14. y = 3 x - 1

Example 3 Represent each function by a graph.

15. CARS A car averages 36 miles per gallon of gasoline. The function
    m = 36 g represents the miles m driven using g gallons of gasoline.


16. FITNESS A health club charges $35 a month for membership fees. The
    equation c = 35 m describes the total charge c for m months of membership.

Graph each equation.

17. y = 0.25x 18. y = x + 0.5 1919 y = 0.5x - 1


18. SHOPPING You buy a DVD for $14 and CDs for $9 each. The equation
    t = 14 + 9 c represents the total amount t that you spend if you buy
    1 DVD and c CDs. Represent this function by a graph.

B

385_390_C07_L1_895130.indd 388 12/31/09 4:24 PM