Question

determine a razão e classifique a PA (x-8), 2x, (2x+12)?

Answer 1

P.A.(X - 8 ; 2 X ; 2 X + 12)
r = a 2 - a 1
r = 2 x - (x - 8)
r = 2 x - x + 8
r = x + 8
r = 2 x + 12  - 2 x
r = 12
igualando as equações,fica:
x + 8 = 12
x = 12 - 8
x = 4
a 1 = x - 8
a 1 = 4 - 8
a 1 = -4
a 2 = 2 x
a 2 = 2.4
a 2 = 8
a 3 = 2 x + 12
a 3 = 2.4 + 12
r = 8  + 12
a 3 = 20
P.A.((-4;8;20)
r = a 2 - a 1
r = 8 - (-4)
r = 8 + 4
r = 12