Question

4-SE A=2⁰-4¯¹ E B=4⁰-2¯¹, ENTÃO A+B É: *

A) -5/4

B) 4/5

C) 0

D) 5/4

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Answer 1

Propriedades de potência:

$a^0=1$

$a^{-n}=\frac{1}{a^n}$

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$A=2^0-4^{-1}\\\\A=1-\frac{1}{4}\\\\\\B=4^0-2^{-1}\\\\B=1-\frac{1}{2}\\\\\\A+B=(1-\frac{1}{4})+(1-\frac{1}{2})\\\\A+B=(\frac{4}{4}-\frac{1}{4})+(\frac{2}{2}-\frac{1}{2})\\\\A+B=\frac{3}{4}+\frac{1}{2}\\\\A+B=\frac{3+2}{4}\\\\A+B=\frac{5}{4}$