MODULAR ARITHMETIC

what is the value of 70^-1 mod 101
Is its value similar to that of what is calculated in 70 x b = 1 mod 101
where b is the multiplicative inverse of 70 .

b is not necessarily 1/70,rather it is just some integer which satisfies the equation you have stated,i.e,70*b congruent to 1 mod 101