Practice!

Sample Problem

x

1

2

3

4

n

y

4

7

10

13

 

 

Fill in the blank above. Write your answer in the form “an + b” where a and b are either positive or negative constants (or 0) .

Solution

The y-value increases 3 for every 1 x-value. Thus, we know that the first part of the equation is 3x.

Plugging 3x into the first column of the table, we have 3 (1) + b = 4. b must be equal to 1.

The pattern is y = 3x + 1, so the blank should be filled as “3n + 1,”