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A multiplicative inverse of 5 mod7 would be a number n ( not a unique one) such that 5n=1

Let's look at the possible numbers

5x1=5mode 7
5x2=10=3 mod 7
5x3=15=1 mod 7 THAT WILL DO IT

3 is the multiplicative inverse of 5 mod 7.

What about the others? 5x4=20, that is -1 mod 7 or 6
5x5=25 which is 4 mod 7
5x6=30 which is -5 or 2 mod 7

How did we know it existed? Because 7 is a prime. For every Prime number p and positive integer n, there exists a finite field with pn elements. This is an important theorem in abstract algebra. Since it is a field, it must have a multiplicative inverse. So the numbers mod 7 make up a field and hence have a multiplicative inverse.

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Q: A multiplicative inverse of 5 module 7 is?
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How do you find the multiplicative inverse of a fraction?

Swap the numerator and denominator. For example, the multiplicative inverse of 5/7 is 7/5


What is an example of multiplicative inverse?

A multiplicative inverse is the same as a reciprocal. The multiplicative inverse of x is 1/x. So, the multiplicative inverse of 4 is 1/4; or 7 is 1/7 and of 0.2 is 1/0.2 = 5.


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The multiplicative inverse means, what do I multiply my number by to get an answer of 1? ex: The multiplicative inverse of 5 is 1/5. 5 * (1/5) = 1 If your number is a fraction to begin with, flip it over. ex: The mult. inverse of 22/7 is 7/22 (22/7)*(7/22) = 1


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38/7 x 7/38 = 1 = multiplicative inverse 38/7 + -38/7 = 0 = additive inverse


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Assuming the question is about the multiplicative inverse, the answer is, -1. It is its own multiplicative inverse.


What is the inverse of -7 plus 5?

It depends on whether you mean additive inverse or multiplicative inverse.


Multiplicative inverse of a negative number?

The multiplicative inverse is the negative of the reciprocal of the positive value. Thus the multiplicative inverse of -7 is -1/7.


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The multiplicative inverse of -24/7 is -7/24


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First convert it into an improper fraction: 5 3/7 becomes 38/7. This is clear because "5" is simply "35/7" (do the math yourself) and 35/7 + 3/7 = 38/7. Additive inverse means "negative." Thus, the "additive inverse" of 38/7 is -38/7. This is true because 38/7 added to -38/7 is 0. That is the definition of an additive inverse. Multiplicative inverse means "reciprocal." Thus, the "multiplicative inverse" of 38/7 is 7/38. This is true because 38/7 multiplied by 7/38 is 266/266, or 1. That is the definition of multiplicative inverse.


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It is 1/7. When you multiply (1/7) by 7 you get 1 as a result.