### Home > CCA > Chapter Ch7 > Lesson 7.2.2 > Problem 7-99

7-99.

If , find the value of the expressions in parts (a) through (c) below. Then complete parts (d) through (f).

*7-99 HW eTool*(Desmos). Homework Help ✎

Substitute −1 for

*x*and simplify.*f*(−1) = 3(2)^{−1}

Refer to part (a).

Refer to part (a).

What value of

*x*gives*f*(*x*) = 12?Substitute 12 for

*f*(*x*) and solve for*x*.*x*= 2Where does the graph of this function cross the

*x*-axis? The*y*-axis?A function crosses the

*x*-axis at*y*= 0, and a function crosses the*y*-axis at*x*= 0.If

, find.

Use the eTool below to find the value of each expression in parts (a) through (c).

Click on the link at right for the full eTool version: CCA 7-99 HW eTool