Respuesta :

[tex] \dfrac{a^2 - b^2}{a+b} = 12[/tex]

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Factorise a² - b² :
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[tex] \dfrac{(a+b)(a-b)}{a+b} = 12[/tex]

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 Crossed out common factors, (x + a) :
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[tex]a- b = 12[/tex]
[tex] \frac{ {a}^{2} - {b}^{2} }{a + b} = 12 \\
\frac{(a - b)(a + b)}{a + b} = 12 \\
a - b = 12[/tex]

a - b = 12

Hope this helps.