Question

Boa Noitee Pessoal, alguem podi me ajudar com essa conta?

a) Log base 2 ( 2x^2+5x+4)=4

b) log base de Raiz 3 ( 3x^2+7x+3)=o

Answer 1

Ola Gaby

a) 

4 = log2(16)

log2(2x² + 5x + 4) = log2(16)

2x² + 5x + 4 = 16

2x² + 5x - 12 = 0

delta
d² = 25 + 96 = 121
d = 11

x1 = (-5 + 11)/4 = 6/4 = 3/2
x2 = (-5 - 11)/4 = -16/4 = -4

b)

log√3(3x² + 7x + 3) = 0

log(3x² + 7x + 3)/log(√3) = 0

2*log(3x² + 7x + 3)/log(3) = 0

log(3x² + 7x + 3) = log(1)

3x² + 7x + 2 = 0

delta
d² = 49 - 24 = 25
d = 5

x1 = (-7 + 5)/6 = -2/6 = -1/3
x2 = (-7 - 5)/6 = -12/6 = -2

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