Question

escreva a forma fatorada das funções quadraticas abaixo


a) y=x² - 2x - 3


b) y= 3x² + 8x

Answer 1

$Forma~~fatorada \\ \\ a) \\ y=x^2-2x-3 \\ \\ Colocar~~na~~forma \\ \\ (x+a)(x+b)=\mapsto x^2+(a+b)+ab \\ \\ onde \\ a+b=-2 \\ a.b=-3 \\ \\ fatores~~de~~3\mapsto3~~e~~1~~que~~ser\tilde{a}o~~os~~n\º~~-3~~e~~1 \\ \\S= -3+1=-2 \\ P=(-3)(1)=-3 \\ \\ logo~~forma~~fatorada \\ \\ y=(x-3)(x+1$
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$b) \\ y=3x^2+8x \\ \\ x~~como~~fator~~comum~~em~~evid\hat{e}ncia \\ \\ y=x(3x+8)$