Question

Sabendo-se que 5^2x + 3 =
625, tem-se que x^4x vale: 










1








1/4








2








1/2








4

Answer 1

$5^{2x+3} =625$

$5^{2x+3} = 5^{4}$

$2x+3=4$

$2x=1$

$x= \frac{1}{2}$

$x^{4x} = ( \frac{1}{2} )^{4.( \frac{1}{2} )}= ( \frac{1}{2} )^{2}= \frac{1}{4}$

Answer 2

$5^{2x+3}=625 \\ \\ 5^{2x+3}=5^4 \\ \\ 2x+3=4 \\ \\ 2x=1 \\ \\ x= \frac{1}{2} \\ \\ \\ x^{4x} \\ \\ ( \frac{1}{2})^{4. \frac{1}{2}$

$( \frac{1}{2})^{ \frac{4}{2}$

$( \frac{1}{2})^2 \\ \\ =( \frac{1}{4})$