Question

d) resolva a equação do 2°grau 5 x2 - 11x + 2 = 0
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Answer 1

Resposta:

Explicação passo-a-passo:

$\displaystyle Aplicando~a~f\'{o}rmula~de~Bhaskara~para~5x^{2}-11x+2=0~~\\e~comparando~com~(a)x^{2}+(b)x+(c)=0,~temos~a=5{;}~b=-11~e~c=2\\\\\Delta=(b)^{2}-4(a)(c)=(-11)^{2}-4(5)(2)=121-(40)=81\\\\x^{'}=\frac{-(b)-\sqrt{\Delta}}{2(a)}=\frac{-(-11)-\sqrt{81}}{2(5)}=\frac{11-9}{10}=\frac{2 \div2}{10 \div2}=\frac{1}{5}\\\\x^{''}=\frac{-(b)+\sqrt{\Delta}}{2(a)}=\frac{-(-11)+\sqrt{81}}{2(5)}=\frac{11+9}{10}=\frac{20}{10}=2\\\\S=\{\frac{1}{5},~2\}$