Question

F- ( x + 7) . ( X + 5)

Answer 1

x1=-5 e x2 -7

Explicação passo-a-passo:

$(x+7)*(x+5)=\\\mathrm{Aplique\:o\:metodo\:FOIL}:\quad \left(a+b\right)\left(c+d\right)=ac+ad+bc+bd\\a=x,\:b=7,\:c=x,\:d=5\\\\=xx+x\cdot \:5+7x+7\cdot \:5\\=xx+5x+7x+7\cdot \:5\\=x^2+12x+35$$x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}\\\mathrm{Para\:}\quad a=1,\:b=12,\:c=35\\\\x_{1,\:2}=\frac{-12\pm \sqrt{12^2-4\cdot \:1\cdot \:35}}{2\cdot \:1}\\x_{1,\:2}=\frac{-12\pm \:2}{2\cdot \:1}\\x_{1}=\frac{-10}{2\cdot \:1}=\frac{-10}{2}=-\frac{10}{2}=-5\\\\\x_{2}= \frac{-12-2}{2\cdot \:1}=\frac{-14}{2\cdot \:1}=\frac{-14}{2}=-\frac{14}{2}=-7\\\\{x_{1}=-5 , x_{2}=-7}$