Hello :
all n in N ; n(n+1)(n+2) = 3a a in N or : <span>≡ 0 (mod 3)
1 ) n </span><span>≡ 0 ( mod 3)...(1)
n+1 </span>≡ 1 ( mod 3)...(2)
n+2 ≡ 2 ( mod 3)...(3)
by (1), (2), (3) : n(n+1)(n+2) ≡ 0×1×2 ( mod 3) : ≡ 0 (mod 3)
2) n ≡ 1 ( mod 3)...(1)
n+1 ≡ 2 ( mod 3)...(2)
n+2 ≡ 3 ( mod 3)...(3)
by (1), (2), (3) : n(n+1)(n+2) ≡ 1×2 × 3 ( mod 3) : ≡ 0 (mod 3) , 6≡ 0 (mod)
3) n ≡ 2 ( mod 3)...(1)
n+1 ≡ 3 ( mod 3)...(2)
n+2 ≡ 4 ( mod 3)...(3)
by (1), (2), (3) : n(n+1)(n+2) ≡ 2×3 × 4 ( mod 3) : ≡ 0 (mod 3) , 24≡ 0 (mod3)
Answer:
A
Step-by-step explanation:
8 times 1.75 is 14.
Area of a triangle = (height * base ) / 2
height = (Area * 2) / base
height = (49.5 * 2) / 9
height = 99 / 9
height = 10 cm²
Answer:
line b
Step-by-step explanation:
y = -2x+2 has a slope of -2 (means it's going downhill) and a y-intercept of 2. Line b is the only line that matches this description.
Answer:
Step-by-step explanation:
We are asked to find the measure of each exterior angle of a regular dodecagon.
We know that a regular dodecagon is a 12 sided regular polygon with each side equal.
We know that measure of each angle of n-sided regular polygon can be found using formula:
Upon substituting 
in above formula, we will get:
Therefore, the measure of each exterior angle of a regular dodecagon is 30 degrees.
