Question

01 -determine o conjunto solução de cada uma das seguintes equações do 2º grau, no conjunto IIR

RESPOSTAS COM CALCULO

Answer 1

$a) x^{2} - 12=0 =\ \textgreater \ x^{2} =12=\ \textgreater \ x=+- \sqrt{12} = +-2\sqrt{3} \\ b) x^{2} -1=0=\ \textgreater \ x^{2} =1=\ \textgreater \ x= +-\sqrt{1}=\ \textgreater \ x=+-1 \\ c) x^{2} -16=0=\ \textgreater \ x^{2} =16=\ \textgreater \ x= +-\sqrt{16}=\ \textgreater \ x=+-4 \\ d)5 x^{2} -3x=0 =\ \textgreater \ \frac{-b+- \sqrt{ b^{2}-4ac }}{2a}=\ \textgreater \ \frac{-(-3)+- \sqrt{(-3)^2-4*5*0} }{2*5}=\ \textgreater \ \frac{3+-3}{10}= \\ x'= \frac{3+3}{10}=0,6= \frac{6}{10}=\ \textgreater \ \frac{3}{5} \\ x"= \frac{3-3}{10}= 0 \\ f) x^{2}-64=0=\ \textgreater \ x^{2} =64=\ \textgreater \ x= +-\sqrt{64}=\ \textgreater \ x=+-8 \\ g)x^2-16=0=\ \textgreater \ x= +-\sqrt{16}=\ \textgreater \ x=+-4$
h)7x^2-x=0=>x(7x-1)=0=>7x-1=0=>7x=1=>x=1/7
i)-9x^2=16=>-x(-1)=16(-1)=>x=-16/9=>x=(-16/9)=√-16/9=√-4/3
j)-7x^2+28=0=>-7x(-1)=28(-1)=>7x^2/7=28/7=>x^2=4=>x=+-√4=>x=+-2
k)x^2-20=0=>x=√20=2√5
$l)-15x^{2} -5x=0=\ \textgreater \ \frac{-(-5)+- \sqrt{( -5)^{2}-4*(-15)*0 } }{2*-15}= \frac{5+- \sqrt{25} }{-30}= \\ x'= \frac{5+5}{-30} = -\frac{10}{30}=\ \textgreater \ -\frac{1}{3} =0.33333... \\ x"= \frac{5-5}{-30}= \frac{0}{-30}=0$