Question

Determine o valor de x, de modo que os termos (4x, 2x+1, 6x) nessa ordem formem uma P.A.?

Answer 1

$P.A(4x,2x+1,6x)\\\\a_1=4x\,\,\,\,\,a_2=2x+1\,\,\,\,\,a_3=6x\\\\a_2-a_1=a_3-a_2\\\\2x+1-4x=6x-(2x+1)\\\\-2x+1=6x-2x-1\\\\-2x-6x+2x=-1-1\\\\-6x=-2\\\\x=\dfrac{-2}{-6}\\\\\\\boxed{x= \dfrac{1}{3}}$