Question

5) Resolva as equações completas do
2°grau.
a) 4 x2 – 20 x + 9 = 0

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Answer 1

Resposta:

a resposta é 172 ok

Explicação passo-a-passo:

espero ter ajudado

Answer 2

Resposta:

Explicação passo-a-passo:

$\displaystyle Aplicando~a~f\'{o}rmula~de~Bhaskara~para~4x^{2}-20x+9=0~~\\e~comparando~com~(a)x^{2}+(b)x+(c)=0,~temos~a=4{;}~b=-20~e~c=9\\\\\Delta=(b)^{2}-4(a)(c)=(-20)^{2}-4(4)(9)=400-(144)=256\\\\x^{'}=\frac{-(b)-\sqrt{\Delta}}{2(a)}=\frac{-(-20)-\sqrt{256}}{2(4)}=\frac{20-16}{8}=\frac{4 \div4}{8 \div4}=\frac{1}{2}\\\\x^{''}=\frac{-(b)+\sqrt{\Delta}}{2(a)}=\frac{-(-20)+\sqrt{256}}{2(4)}=\frac{20+16}{8}=\frac{36\div4}{8 \div4}=\frac{9}{2}\\\\S=\{\frac{1}{2},~\frac{9}{2}\}$