Question

quais as raizes da equação 3x2-4x-7=0?​

Answer 1

Resposta:

Explicação passo-a-passo:

$\displaystyle Aplicando~a~f\'{o}rmula~de~Bhaskara~para~3x^{2}-4x-7=0~~\\e~comparando~com~(a)x^{2}+(b)x+(c)=0,~temos~a=3{;}~b=-4~e~c=-7\\\\\Delta=(b)^{2}-4(a)(c)=(-4)^{2}-4(3)(-7)=16-(-84)=100\\\\x^{'}=\frac{-(b)-\sqrt{\Delta}}{2(a)}=\frac{-(-4)-\sqrt{100}}{2(3)}=\frac{4-10}{6}=\frac{-6}{6}=-1\\\\x^{''}=\frac{-(b)+\sqrt{\Delta}}{2(a)}=\frac{-(-4)+\sqrt{100}}{2(3)}=\frac{4+10}{6}=\frac{14\div2}{6\div2}=\frac{7}{3}\\\\\\S=\{-1,~\frac{7}{3}\}$