Answer:
r = 9
Step-by-step explanation:
cross multiply
9 * r = 81
9r = 81
divide both sides by 9
r= 81/9
r = 9
Answer:
17.1 cm
Step-by-step explanation:
A screw driver is a mechanical tool or device which is mainly used for screwing the screws and unscrewing them. It is also used for removing the nuts and bolts and also serves a variety of uses.
It is typically made of steel and has a handle and a shaft which ends as a tip.
In the context, the length of the screw driver from the given figure expressed to the nearest tenth of a centimeter is 17.1 cm.
It is also equivalent to
inch.
With what? I might be able to help
Answer:
3, 6, 9, 12 is not geometric
Step-by-step explanation:
A geometric progression has a common ratio r between consecutive terms.
3, 6, 9 , 12
has a common difference of 3 between terms and is arithmetic
1, 5, 25, 125
r = 5 ÷ 1 = 25 ÷ 5 = 125 ÷ 25 = 5 ← geometric
4, 8, 16, 32
r = 8 ÷ 4 = 16 ÷ 8 = 32 ÷ 16 = 2 ← geometric
2, 6, 18, 54
r = 6 ÷ 2 = 18 ÷ 6 = 54 ÷ 18 = 3 ← geometric
Answer:
n(n-1) =156
n^2-n=156
n^2-n-156=0
(n-13) (n+12) =0
so n=13 because it's an ordinary number and can't be negative