Question

Calcule x, sabendo que bc//mn

Answer 1

a)x/x + 5 = 2 x/x + 20
2 x (x + 5)= x( x + 20)
2 x² + 10 x = x² + 20 x
2 x² - x² + 10 x - 20 x = 0
x² - 10 x = 0
x( x - 10 ) = 0
x = 0
x - 10 = 0
x = 10
s = 10
Resposta O valor de x = 10

b)x/x + 3 = x + 2 / 2 x
x(2 x) = (x + 2) ( x + 3)
2 x² = x² + 5 x + 6 
2 x² - x² - 5 x - 6 = 0
x² - 5 x - 6 = 0
Δ = b² - 4 a . c
Δ= (-5)² - 4 . 1. -6
Δ = 25 + 24
Δ = 49 ⇒ √ 49 = 7
x = - b + ou - 7/2
x´= - (-5) + 7/2
x = 5 + 7/2
x = 12/2
x´= 6
x" = 5 - 7/2
x" = -2/2
x" = -1 
s = 6
Resposta O valor de x = 6