Question

determine o valor de x na PA( 8x,4x+2,12x)

Answer 1

a1 = 8x
a2 = 4x + 2
a3 = 12x

( a1 + a3)/2 = a2
( 8x + 12x)/2  = (4x + 2)/1
20x/2 = (4x + 2)/1
20x = 2 ( 4x + 2)
20x = 8x + 4
20x - 8x = 4
12x = 4
x = 4/12 = 1/3 ***

a1 = 8x = 8(1/3) = 8/3 ***
a2 = 4x + 2=  4 ( 1/3) + 2/1 = 4/3 + 2/1 = ( 4 + 6)/3 = 10/3 ***
a3 = 12x = 12 * 1/3 = 12/3 = 4 ***