Question

Greg chose C as the answer. How might he have gotten that answer?

Answer 1

Given:

The equation is

`-0.4x+0.05y-1.25=0`

Where, y is the total cost and x is the number of months.

To find:

The y-intercept of the line represented by this equation.

Solution:

We have,

`-0.4x+0.05y-1.25=0`

Isolate y variable.

`0.05y=0.4x+1.25`

Divide both sides by 0.05.

`y=(0.4x+1.25)/(0.05)`

`y=(0.4x)/(0.05)+(1.25)/(0.05)`

`y=8x+25`

Putting x=0, we get

`y=8(0)+25`

`y=0+25`

`y=25`

Therefore, the y-intercept of the given equation is 25 and the correct option is D.