geometry HELP!!!!!!!!!!!11

The first term in a g.p. is $a$

The second term is $ar$

The third term is $ar^2$ and so on.

Does that help?

i know that already..what do i do with that?

a + ar = 108

ar² + ar³ = 12

Those are your simultaneous equations. Find 'a' and 'r'.

thanks
i actually wrote down exactly what you have given me then didnt know what to do

thanks
i actually wrote down exactly what you have given me then didnt know what to do

nor do I lol

Just to expand on what thegodofgod said, notice you can take a factor of a out in the first case or ar² in the second case. Then you can divide one equation from the other to let you find r, and then substitute back to find a.

And on another note, this isn't geometry (although it is a geometric progression... but for some reason geometry and geometric sequences/series don't have a great deal to do with each other).

Just to expand on what thegodofgod said, notice you can take a factor of a out in the first case or ar² in the second case. Then you can divide one equation from the other to let you find r, and then substitute back to find a.

And on another note, this isn't geometry (although it is a geometric progression... but for some reason geometry and geometric sequences/series don't have a great deal to do with each other).

do i times a + ar = 108 by three

nor do I lol

EDIT:

a + ar = 108

ar² + ar³ = 12

a --> ar² = multiplying by r² (same with other).

Hence:

12 = 108 r²

r² = 12/108

r² = 1/9

r = +- 1/3

Then sub that into any of the equations to get the 'a' value.

Just to expand on what thegodofgod said, notice you can take a factor of a out in the first case or ar² in the second case. Then you can divide one equation from the other to let you find r, and then substitute back to find a.

And on another note, this isn't geometry (although it is a geometric progression... but for some reason geometry and geometric sequences/series don't have a great deal to do with each other).

EDIT: Did I take ages to respond or were the replies before me really quick?

is a +- 162

No: If you take the positive 1/3,

a + ar = 108

a(1+r) = 108

a = 108 / (1+r)

a = 108 / (1 + 1/3)

a = 108 / (4/3)

a = 108 x (3/4)

a = 81

i just realised your the TSR people..:/
if i realised wouldnt have asked you so many question lol
normally you people give me warnings

i just realised your the TSR people..:/
if i realised wouldnt have asked you so many question lol
normally you people give me warnings