X=-1
-1x2 + 5x-1 +7 = 0
-7+7 =0
0=0
The expression we need to solve is:

To solve this problem, we need to not that we can simplify the fraction 2/10 by dividing both number by 2:
Well every year it grows 8 inches which means that for every one year it grows 8 inches.
BUT, the tree started out 14 inches so every year you have to add the original 14 inches.
So your equation looks like this:
h=8a+14
Hope this helps :)