Lista de exercícios do ensino médio para impressão
Choose the incorrect statement:
a)
$5^{\large2}\,=\,25$
b)
$5^{\large3}\,=\,125$
c)
$(-5)^{\large2}\,=\,25$
d)
$(-5)^{\large3}\,=\,-125$
e)
$(-5)^{\large n}\,=\,5^{\large n},\,\forall\,n\,\in\,\,\mathbb{N}$

×
Choose the incorrect statement from the following:
a)
$-5^2 = -25$
b)
$(-5)^2 = 25$
c)
$-5^3 = -125$
d)
$(-5)^3 = -125$
e)
$(-5)^n = -5^n, \, \forall\; n \in \mathbb{N}$

×
Choose the incorrect:
a)
$5^0 = 1$
b)
$(-2,3)^0 = 1$
c)
$5^{-2}\,=\,\dfrac{1}{25}$
d)
$(-5)^{-2}\,=\,\dfrac{1}{25}$
e)
$-5^{-2}\,=\,\dfrac{1}{25}$

×
Choose the statement that is incorrect:
a)
$5^{\large 3}\times 5^{\large 4} = 5^{\large 7}$
b)
$2^{\large 5} \div 2^{\large 3} = 2^{\large 2}$
c)
$(0,5)^{\large 2} \times (0,2)^{\large 2} = (0,1)^{\large 2} = 0,01$
d)
$(0,4)^{\large -2} \times (-5)^{\large -2} = 0,25$
e)
$\dfrac{(0,05)^{\large 3}}{5^{\large 3}}\,=\,10^{\large -3}$

×
The expression $\phantom{X}[\dfrac{\sqrt{a\;+\;b}\;-\;\sqrt{a}}{b}]^{-1}\phantom{X}$ , where $\;a\;$ and $\;b\;$ are positive numbers, is equivalent to:
a)
$\;\dfrac{1}{b}$
b)
$\;b$
c)
$\;\dfrac{b \; + \; \sqrt{a}}{\sqrt{a\;+\;b}}$
d)
$\;\sqrt{b}$
e)
$\;\sqrt{a \; + \; b}\; + \; \sqrt{a}$

×
After subtracting $\phantom{X}\dfrac{5}{8\;-\;3\sqrt{7}}\phantom{X}$ from $\phantom{X}\dfrac{12}{\sqrt{7} \;+\;3}\phantom{X}$ the result is:
a)
$81 - 4\sqrt{7}$
b)
$22 + 21\sqrt{7}$
c)
$-22\;-\;21\sqrt{7}$
d)
$41\sqrt{7}\;-\;81$
e)
none of these are correct.

×
The numbers $\phantom{X}\sqrt[\Large 4]{5}\;$, $\phantom{X}\sqrt[\Large 3]{3}\phantom{X}$ and $\phantom{X}\sqrt{2}\;\;$ are arranged:
a)
in descending order
b)
in ascending order
c)
in non-descending order
d)
the value of the last term is half of the sum of the first term and the second term
e)
none of these