1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
kkurt [141]
2 years ago
11

What is the smallest integer $n$, greater than $1$, such that $n^{-1}\pmod{130}$ and $n^{-1}\pmod{231}$ are both defined?

Mathematics
1 answer:
olasank [31]2 years ago
3 0

First of all, the modular inverse of n modulo k can only exist if GCD(n, k) = 1.

We have

130 = 2 • 5 • 13

231 = 3 • 7 • 11

so n must be free of 2, 3, 5, 7, 11, and 13, which are the first six primes. It follows that n = 17 must the least integer that satisfies the conditions.

To verify the claim, we try to solve the system of congruences

\begin{cases} 17x \equiv 1 \pmod{130} \\ 17y \equiv 1 \pmod{231} \end{cases}

Use the Euclidean algorithm to express 1 as a linear combination of 130 and 17:

130 = 7 • 17 + 11

17 = 1 • 11 + 6

11 = 1 • 6 + 5

6 = 1 • 5 + 1

⇒   1 = 23 • 17 - 3 • 130

Then

23 • 17 - 3 • 130 ≡ 23 • 17 ≡ 1 (mod 130)

so that x = 23.

Repeat for 231 and 17:

231 = 13 • 17 + 10

17 = 1 • 10 + 7

10 = 1 • 7 + 3

7 = 2 • 3 + 1

⇒   1 = 68 • 17 - 5 • 231

Then

68 • 17 - 5 • 231 ≡ = 68 • 17 ≡ 1 (mod 231)

so that y = 68.

You might be interested in
Larry says all
MaRussiya [10]

Answer:

larry is incorrect because the number 2 is not a composite number, although numbers 12, 22, 32, 42, 52, 62, 72, 82, and 92 are composite, 2 isn't

6 0
3 years ago
Find the volume of the cone that sits on top of the cylinder
puteri [66]

Answer:

Vc = (π/3)✓17 ≈ 4.12 ft³

Step-by-step explanation:

h = ✓(4²+1²)

h = ✓17

V = πr²h/3

V = π(1)²✓17/3

V = (π/3)✓17 ≈ 4.12

8 0
2 years ago
What is the shortest possible distance between the houses
Iteru [2.4K]

Answer: 17 easy how could you not get it but yea thats that

Step-by-step explanation:

7 0
3 years ago
Read 2 more answers
Arrange the numbers in increasing order. -3, +8, -4, +1, -7
Bad White [126]

Answer:

-7,-4,-3,+1,+8

Step-by-step explanation:

The bigger the negative number, the less it's worth

3 0
2 years ago
Read 2 more answers
A rocket is launched from a tower what time will the rocket reach its max
Lena [83]

Answer:

Step-by-step explanation:

A science class designed a ball launcher and tested it by shooting a tennis ball up and off the top of a 15-story building. They determined that the motion of the ball could be described by the function: h(t) = -16t2 + 144t + 160, where ‘t’ represents the time the ball is in the air in seconds and h(t) represents the height, in feet, of the ball above the ground at time t.

a) Graph the function h(t) = -16t2 + 144t + 160 (see below)

      b) What is the height of the building?

The height of the building is also the height of the tennis ball before it is launched into the air. This occurs when t=0 so substitute 0 for t and you get:

H(0) = -16(0)2 + 144(0) + 160

The height of the building is 160 feet.

 c) At what time did the ball hit the ground?

The ball hits the ground when the height is 0. Therefore, we are looking for a solution to: -16t2 + 144t + 160 = 0

Use the quadratic formula or put this into a calculator. The solution is t=10 and -1, but only 10 makes sense. Therefore, the ball hits the ground at 10 seconds.

  d) At what time did the ball reach its maximum height?

You can put this into the calculator or you can realize that the maximum height is also

− the vertex. The x-value (‘t’ in this case) is 2

−144

which is (2)(−16) = 4.5.

Therefore, the ball reached its maximum height at 4.5 seconds.

   e) What is the maximum height of the ball?

We calculated the time of the maximum height (4.5 seconds). Therefore, substitute 4.5 into the function to find the maximum height.

-16(4.5)2 + 144(4.5) + 160

The maximum height is 484 feet.

5 0
2 years ago
Other questions:
  • What’s the place value of 9 in 987,164
    9·2 answers
  • Interquartile range n stuff
    7·1 answer
  • Try this, please!
    8·1 answer
  • Mark and Hayden won a raffle and decide to split the money using the ratio 9:8. If Hayden received $64, which of the following w
    6·1 answer
  • Two integers with different signs that have the sum of -25
    9·1 answer
  • How do I solve 12x^2-89x-56 factor by grouping
    8·1 answer
  • Alan's dogs have a total of 24 legs (l). If each dog has 4 legs, which equation gives the number of dogs (d) that Alan has?
    9·1 answer
  • The center of a circle is at (−3, 1) and its radius is 9. What is the equation of the circle?
    14·1 answer
  • On a field trip, there are 3 adults for every 45 students. Which graph models a relationship
    9·1 answer
  • Please help i dont get this at all so please i will highly appreciate it .Thank youuu!!!
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!