Question

A home uses 8 gallons of oil each day for heat. If its oil storage tank is filled to 275 gallons, the function y  275  8x represents the number of gallons remaining in the tank after x days of use. Explain what the x-intercept represents. Then determine when the tank would be

Answer 1

17 days

Explanation:

+y+=+275+-+8x+

The x-intercept is the point ( x,0 )

Since y=0 at the x-intertcept, this

is the point where the remaining gallons

of oil in the tank = 0, and the value

of x will be the number of days to

use up all 275 gallons

The tank will be half full when the remaining

gallons = +275%2F2, so I can say:

275%2F2=275+8x

Multiply both sides by 2

275+=550+16x

16x=550+275

16x=275

x=17.1875

The tank will be half full during the 17th day