Question

Two years after it’s purchase, if Manuel’s gift card is unused, the automatic decrease on the gift card balance is given by the equation b = 50 - 5m, where m is the number of months beyond two years.

Is this model of the siu action linear? If it is, what are the slope and y-intercept?

A. linear: slope = -10, y-intercept = 5
B. linear: slope = -50, y-intercept = 5
C. linear: slope = -5, y-intercept = 50
D. not linear

Answer 1

This function is linear. True

The slope of this function is 50. False

The y-intercept of this function is 50. True

Answer 2

Option C. linear: slope = -5, y-intercept = 50

Explanation:

Let

b ----> is the automatic decrease on the gift card balance

m ----> is the number of months beyond two years

we know that

The equation of the line into slope intercept form is equal to

`y=mx+b`

where

m is the slope

b is the y-intercept

In this problem the linear equation that represent this situation is

`b=-5m+50` ---> equation of the line into slope intercept form

so

The slope is -5

The y-intercept is 50