X 0 1 2 3 4. y 8 14 20 26 32

are ya tryin to ask something or is this a statement

8.75

how-to:

first, we need to find what we have to work with.

since i know that we have 7 (years) and 0.8 (inches), we can use these to solve and find the equation!

secondly, what you want to do, is see that we need to know how much growth out of the 0.8 inches he got in only 1 year, instead of 7 years.

let's try to divide.

7 ÷ 0.8 = 8.75

this would be 35. 35 + 5 = 40. you take the known constant and subtract by the answer of the equation and you get y.