Question

encontre as raízes das equações incompletas do segundo grau:
a) X²-5X=0
b) 5X²+X=0
c) X²-64=0
d) X²+16=0
e) -7X²+28=0
f) (X-7)-(X-3)+10X=30​

Answer 1

$\large\boxed{\boxed{{Ol\'a\:Salesrian}}}}}$

$A)\:x^2-5x=0$

$x(x-5)=0$

$x=0\:\:V\:\:x=5$

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$B)\:5x^2+x=0$

$x(5x-1)=0$

$x=0\:\:V\:\:5x=1$

$x=0\:\:V\:\:x=\frac{1}{5}$

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$C)\:x^2-64=0$

$x^2=64$

$x=±sqrt{64}$

$x=±8$

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$D)\:x^2+16=0$

$x^2=-16$

$x=±\sqrt{-16}$

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$E)\:-7x^2+28=0$

$-7x^2=-28$

$x^2=\frac{-28}{-7}$

$x^2=4$

$x=±sqrt{4}$

$x=2$

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$F)\:(x-7)-(x-3)+10x=30$

$(x-7)(-x+3)+10x=30$

$-x^2+3x+7x-21+10x=30$

$-x^2+10x+10x-21=30$

$-x^2+20x-21-30=0$

$-x^2+20x-51=0$

onde:

a = —1 ; b = 20 e c = —51

$\Delta=20^2-4.(-1).(-51)$

$\Delta=400-204$

$\Delta=196$

$x_{1}=\frac{-20+\sqrt{196}}{2.(-1)}$

$x_{1}=\frac{-20+14}{-2}$

$x_{1}=\frac{-6}{-2}$

$x_{1}=3$

$x_{2}=\frac{-20-14}{-2}$

$x_{2}=\frac{-34}{-2}$

$x_{2}=17$

:::::::Espero ter ajudado:::::::