Question

o valor númerico para
$x {}^{2} + 4$
onde x=2 é

a)8
b)4
c)-2
d)-7​

Answer 1

Resposta:

$x^2+4=8\\\\x^2+4-4=8-4\\\\x^2=4\\\\x=\sqrt{4},\:x=-\sqrt{4}\\\\x=2,\:x=-2\\\\2^2 +4= \\\\2^2= 4\\\\4+4= \\\\8$