A 7-inch candle burns at a rate of 2 inches an hour. Which equation represents the relationship between y, the height of the candle in inches, and x, the number of hours the candle burns?

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.

i think it would be 42cm