Student: The smallest number which when subtracted from the sum of squares of 11 and 13 gives a perfect square is\nOptions:\n(A) 1\n(B) 4\n(C) 5\n(D) 9\n(E) 8.
Another student: Let's say, hmmm...

User
11^2 + 13^2 = 121 + 169 = 290\n290 - 1 = 289 = 17^2\n1 must be subtracted to give a perfect square. Final answer: (A).
Assistant