Question

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Answer 1

Resposta:

a)

$x^{2} -4x-5=0\\a=1 \\b=-4\\c=-5\\delta=b^{2}-4ac\\delta=(-4)^{2}-4(1)(-5)\\delta=16+20\\delta=36\\\\x= \frac{-b+-\sqrt{delta} }{2a} \\x=\frac{-(-4)+-\sqrt{36} }{2(1)}\\x=\frac{4+-6}{2}\\\\x_{1}=\frac{4+6}{2}=5\\\\x_{2}=\frac{4-6}{2}=-1$

b)

$x^{2} -5x+6=0\\a=1 \\b=-5\\c=6\\delta=b^{2}-4ac\\\\delta=(-5)^{2}-4(1)(6)\\delta=25-24\\delta=1\\\\x= \frac{-b+-\sqrt{delta} }{2a} \\x=\frac{-(-5)+-\sqrt{1} }{2(1)}\\x=\frac{5+-1}{2}\\\\x_{1}=\frac{5+1}{2}=3\\\\x_{2}=\frac{5-1}{2}=2$

Espero ter ajudado e bons estudos!

Abraços!