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.

Question

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.

anonymous · Answer

(3,17)  and (5,15)

Calculate a line equation in the usual way (x is t, y is h)

Then put t (x) is 8 to find h(y)

anonymous · Answer

would you do y2-y1/x2-x1

anonymous · Answer

Sure, to get the slope, then use one of the points to get c

anonymous · Answer

i got a -1 what do i after that?

anonymous · Answer

then use one of the points to get c

anonymous · Answer

wait how do i do that?

anonymous · Answer

y = mx +c  You just got m, now sub one of the x,y pairs in to get c