Question 1180346
let n the numbers of years for both trees  to reach same height

tree1
a=8, tn  height after n years , d=2

tn = a +(n-1)d
tn= 8 +2n-2
tn =2n+6

Tree 2

tn = 10 +(n-1)1
tn = 9+n

2n+6 = 9+n
n=3