Question

if Tn = n square + 4 and Tn=20 find the value of n

Answer 1

Tn= n²+ 4= 20
or n² = 16
or n= ±4
But n cannot be negative so n=4

Answer 2

n^2 + 4. = 20
n^2. = 20-4=16
n^2=16
n=±4