Question

Sendo 2^x = b, então 2^-2 + 2x vale

a) 3b^2.

b) b/3.

c)b^2/4.

d)4b.

e)2b^2/3.

Answer 1

$2^{-2+2x}= 2^{-2}\cdot2^{2x}= \big(\frac{1}{2}\big)^2 \cdot(2^{x})^2=\frac{1}{4}\cdot b^2= \frac{b^2}{4}$