Answer:
16.8km
Step-by-step explanation:
Arc length = 2πr(θ/360)
=2π(8)(120/360)
=16.7551608191
≈16.8km
Let

be any integer. Then

In other words:
(1) If

is a multiple of 4, then

.
(2) If dividing

by 4 leaves a remainder of 1, then

, since

for some integer

, and from (1) we know that

(because, obviously,

is a multiple of 4).
(3) If instead you get a remainder of 2, then

. This follows from (1) as well.

.
(4) Finally, if you get a remainder of 3, then

.
Assuming the given is: 5u^7 - 21u^7
Since both algebraic terms are identical (both are using u^7), we can subtract the coefficients directly, as in: 5 - 21 = -16
Therefore, 5u^7 - 21u^7 = -16u^7
Answer:
1.D 2.C 3.A 4.B
Step-by-step explanation:
hope this helped