Find an inverse for 43 modulo 660. that is, find an integer s such that 43s=1(mod 660)

307 is an inverse of 43 mod 660

Step-by-step explanation:

We know that given integers and , if , then has an inverse modulo , and using Euclidean algorithm we  find an inverse of expressing 1 as a linear combination of and finding integers and such that , in this case, is an inverse of , i.e., ≡

To find the inverse of 43 mod 600, we need to do two steps:

which implies that gcd(660, 43)= 1 and so 660 and 43 are relatively prime.

   2. Express 1 as a linear combination of 43 and 600.

We work backwards using the equations derived by applying the Euclidean algorithm, expressing each remainder as a linear combination of the associated divisor and dividend:

substitute ,

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Thus 43*307=1+20*660, then by definition of congruence modulo 660, 43*307 ≡ 1 (mod 600) and therefore 307 is an inverse of 43 mod 660.

the anwser is d) 75°

step-by-step explanation:

30005

yes ok