Let x be a positive integer such that \(9x\equiv 1\pmod{25}\). What is the remainder when 11+x is divided by 25?
We have to find a multiple of 9, that when divided by 25 leaves a remainder of 1.
Therefore, 126 is congruent to 1(mod25)...so x = 126 / 9 = 14.
Thus, 14+11=25 and dividing this result by 25 leaves a remainder of 0.
-tertre
