Answer:
[tex]y=4.5t+20\\\\t=20\\y=4.5*20+20\\y=90+20\\y=110[/tex]
Step-by-step explanation:
So when t=0 in the first equation y=20 which is the length as you are just born. How I calculate 4.5 is that I assume:
y=xt+20
for t=10 we have y=65
65=10x+20
10x=45
x=4.5
the equation becomes y=4.5t+20.