1. Find an x-value EXAMPLE 2 Write original function. Substitute 6 for f(x). 8 x = Solve for x. ANSWER When x = 8, f(x) = 6. 6 2x – 10= f(x) = 6. For the function f(x) 2x – 10, find the value of x so that = = 2x – 10 f(x)f(x)

2. Graph a function The gray wolf population in central Idaho was monitored over several years for a project aimed at boosting the number of wolves. The number of wolves can be modeled by the function f(x) = 37x + 7 where x is the number of years since 1995. Graph the function and identify its domain and range. GRAY WOLF EXAMPLE 3

3. SOLUTION To graph the function, make a table. xf(x) 037(0) + 7 = 7 137(1) + 7 = 44 237(2) + 7 = 81 The domain of the function is x  0. From the graph or table, you can see that the range of the function is f(x)  7. Graph a function EXAMPLE 3

4. EXAMPLE 5 GUIDED PRACTICE for Examples 2 and 3 2. WOLF POPULATION Use the model from Example 3 to find the value of x so that f(x) = 155. Explain what the solution means in this situation. 4 ; in 1999, 4 years after 1995, the wolf population will be 155. ANSWER