Let the three gp be a, ar and ar^2
a + ar + ar^2 = 21 => a(1 + r + r^2) = 21 . . . (1)
a^2 + a^2r^2 + a^2r^4 = 189 => a^2(1 + r^2 + r^4) = 189 . . . (2)
squaring (1) gives
a^2(1 + r + r^2)^2 = 441 . . . (3)
(3) ÷ (2) => (1 + r + r^2)^2 / (1 + r^2 + r^4) = 441/189 = 7/3
3(1 + r + r^2)^2 = 7(1 + r^2 + r^4)
3(r^4 + 2r^3 + 3r^2 + 2r + 1) = 7(1 + r^2 + r^4)
3r^4 + 6r^3 + 9r^2 + 6r + 3 = 7 + 7r^2 + 7r^4
4r^4 - 6r^3 - 2r^2 - 6r + 4 = 0
r = 1/2 or r = 2
From (1), a = 21/(1 + r + r^2)
When r = 2:
a = 21/(1 + 2 + 4) = 21/7 = 3
Therefore, the numbers are 3, 6 and 12.
Answer:
666.6667 feet²
Step-by-step explanation:
So.
Since the scale is 1 : 20, we can do 4 x 20 and 5 x 20, Which is 80 and 100.
Find area: 80 x 100 = 8000 we can just add 2 zeros to 80 since it's multiplying by 100.
So it's 8000in²
Then we do 8000 in to feet.
Which is ≈ 666.6667feet
btw it asked for feet so we give them FEET
Answer:
ay bro i go to bear lakes ms wells is really mean
Step-by-step explanation: you hear G
(9/2) (3)
--------- X -----
(2/3) (3)
(27/2)
---------
(2)
(27)
------
(4)
6 and (3/4) calories:1 minute