Given :
A 7-inch candle burns at a rate of 2 inches an hour.
To Find :
An equation represents the relationship between y, the height of the candle in inches, and x, the number of hours the candle burns.
Solution :
We know, linear equation is given by :
At x = 0 -> y = 7
So,
7 = m(0) + c
c = 7 .....1 )
At x = 1 -> y = 5
So,
5 = m(1) + c
c + m = 5 .....2 )
Solving equation 1 and 2 , we get :
m = -2 and c = 7
Therefore, equation is given by y = -2x + 7 .
Hence, this is the required solution.