If 2^x = t, express the following in terms of t:

a. 2^2x+1

b. 2^1-x

2^x = t

a) 2^2x + 1
= (2^x)^2 + 1
= t^2 + 1

b) Assuming you mean 2^(1-x),
= (2^1)/(2^x)
= 2/t