34. Let a, b, c and d be distinct nonnegative integers such that a ^2 − b ^2 = c ^2 − d ^2. What is the least possible value of a + b?

Question

The answer is 3 but I don't know the solution.

Answer 1

My apologies
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3^2 - 0^2 = 5^2 - 4^2 are both equal to 9
a^2 - b^2 = c^2 - d^2 is GIVEN to be true and must hold
integer values of zero or more

So a=3, b=0, c = 5, and d = 4

Notice that a+b = 3