Question

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$8b + 15 = b {}^{2}$

Answer 1

$8b + 15 = {b }^{2} \\ 0 = {b}^{2} - 8b - 15$

$lo \: reacomodamos \\ - 15 - 8b + {b}^{2}$
$5 \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: - b \\ - 3 \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: - b$
$( 5 - b)( - 3 - b) = 0$
$5 - b = 0 \\ 5 = b$
$- 3 - b = 0 \\ - 3 = b$