Question

calcule o valor de: y=2-² + 2² -2¹ / 2-² -2-¹

Answer 1

$\boxed{y=\frac{2^{-2}+2^2-2^1}{2^{-2}-2^{-1}}=\frac{\frac{1}{4}+4-2}{\frac{1}{4}-\frac{1}{2}}=\frac{\frac{1+8}{4}}{\frac{1-2}{4}}=\frac{9}{-1}=-9}$