Question

a) 4x-1=3(x-1) b) 3x(x-2)=2x-4 c) 2x(x-1)=3x+4 (com o calculo pfvr)​

Answer 1

a)

$4x - 1 = 3(x - 1)\\4x - 1 = 3x - 3\\4x - 3x = 1 - 3\\x = -2$

b)

$3x(x - 2) = 2x - 4\\3x^{2} - 6x = 2x - 4\\3x^{2} - 8x + 4 = 0\\\\-8^{2} - 4.3.4 = 64 - 48 = 16\\\\x = (8 +\sqrt16)/ 2.3 = 12/6 = 2\\x = (8 - \sqrt16)/ 2.3 = 4/6 = 2/3\\x = 2,2/3$

c)

$2x(x-1)=3x+4\\2x^{2} -2x = 3x + 4\\2x^{2} -5x -4 = 0\\\\-5^{2} - 4.2.(-4) = 25 - (-32) = 57\\ \\x = (5 +\sqrt57)/2.2 = (5 + \sqrt57)/4\\x = (5 -\sqrt57)2.2 = (5 - \sqrt57)/4\\x = (5 + \sqrt57)/4, (5 - \sqrt57)/4$