Chapter ISG, Problem 3.7STP

a.

To determine

To evaluate the meaning of 30 and 180 in A’s function.

Answer to Problem 3.7STP

180 represents the initial saving and 30 represents the per month saving.

Explanation of Solution

Given information:A’s saving function is,

  $y=30x+180$

Where, “ x” is the number of months.

Evaluation:

180 in the function is the initial money A put into her saving, that is, the money she started her savings with.

30 in the function represents that A’s monthly saving is $30

b.

To determine

To describe the two graphs

Answer to Problem 3.7STP

The two equations are different because the initial point of both line is different.

Explanation of Solution

Given information:A’s saving function is,

  $y=30x+180$

Sam’s saving function is,

  $y=30x+250$

Where, “ x” is the number of months.

Graph:The blue line represents A’s function and green represents Sam’s function

  

Evaluation:The two functions are different as their initial values are different, that is values when x=0 are different. The initial value for A’s line 180 and that for Sam is 250.