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:
x = 2
Step-by-step explanation:
The product of distances from the intersection of secants to the near and far intersections with the circle are the same. For a tangent, the near and far points of intersection with the circle are the same. This relation tells us ...
(2√3)(2√3) = x(x +4)
12 = x² +4x
16 = x² +4x +4 . . . . . add the square of half the x-coefficient to complete the square
4² = (x +2)² . . . . . . . . write as squares
4 = x +2 . . . . . . . . . . positive square root
2 = x . . . . . . . . . . . . . subtract 2
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<em>Alternate solution</em>
If you believe x to be an integer, you can look for factors of 12 that differ by 4.
12 = 1×12 = 2×6 = 3×4
The factors 2 and 6 differ by 4, so x=2 and x+4=6.
Answer:
D
Step-by-step explanation:
Answer:
Before Tax: $240
After Tax: $259.20
Step-by-step explanation:
If we are trying to find the original price then here:
216/1.08 = 200
This took away the tax now we need to take away the discount:
200 x 1.2 = 240
Before Tax: $240
After Tax: $259.20
Answer:
2/18, 1/9
Step-by-step explanation:
5/18 + (-1/6)
-1/6=-3/18
5/18+(-3/18)=
2/18
