help i am in need of help

Sure. The height of the tree is a function of the time in days. Let's call the function h(t) where t is the time in days.
At t=0 we know h(t)=5 centimeters and each day we increase 2.5 centimeters. So our function is
[tex] h(t) = 5 + 2.5 t [/tex]
We want to find t when h(t) = 65 so our equation is
[tex]65 = 5 + 2.5 t [/tex]
That's the answer for the first box. We solve for t:
[tex]65 -5 = 2.5 t[/tex]
[tex]t = (65 - 5)/2.5 = 60/2.5 = 24 \textrm{ days}[/tex]