Question

SHOW YOUR WORK PLEASE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A candle is 17 in. tall after burning for 3 hours. After 5 hours, it is 15 in. tall. Write a linear equation to model the relationship between height h of the candle and time t. Predict how tall the candle will be after burning 8 hours.

Answer 1

h = -t+20

After 8 hours the candle will be 12 inches

Explanation:

We have 2 points (time, inches)

(3,17) and (5,15)

We can find the slope

m = (y2-y1)/(x2-x1)

= (15-17)/(5-3)

= -2/2

= -1

We can use point slope form

y-y1 = m(x-x1)

Replace y with h and x with t

h-17 = -1 (t-3)

Distribute

h-17 = -t+3

Add 17 to each side

h-17+17 = -t+3+17

h = -t+20

After 8 hours

h = -t+20

h = -8+20

h= 12