Question

Alguém que sabe?

2)
Resolva a equação x (x + 5) = 2x + 28, sendo U= R.
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Answer 1

Resposta:

x (x + 5) = 2x + 28, sendo U= R.

x² + 5x = 2x + 28

x² + 5x - 2x - 28 = 0

x² + 3x - 28 = 0

Δ = b² - 4.a.c

Δ= 3² - 4.1.(-28)

Δ = 121

$x=\frac{-3+/-\sqrt{121} }{2}$

$x=\frac{-3+/-11}{2}$

$x=\frac{-3-11}{2}$

$x=\frac{-14}{2}$

$x=-7$

$x=\frac{-3+11}{2}$

$x=\frac{8}{2}$

$x=4$

S = {-7 , 4}

bons estudos!