Answer:
(y - 25) = - 0.25(x - 20)
Step-by-step explanation:
Given that :
Height of candle after burning for 20 minutes = 25 cm
Height after burning for 1 hr (60 minutes) = 10 cm
Height (y) in cm of candle x minutes after being lit:
Using the equation :
(y - y1) = m(x - x1)
m = (change in y / change in x)
Change in height within 60 minutes :
Height at 20 minutes = 25cm
Height after an hour = 10
Change in height per hour = (25 - 10) = 15cm
Hence, m = change in height per minute
15cm / 60 = 0.25cm ( - 0.25) (decrease in height)
y1 = 25 ; x1 = 20
(y - y1) = m(x - x1)
(y - 25) = - 0.25(x - 20)
The difference is -10 because
9-10= 1
-1-10= -11
-11-10= -21
common difference means you add and common ratios means you multiply.
hope this helps!
