Let x and y be two 2-digit numbers such that y is obtained by reversing the digits of x. Suppose they also satisfy x2–y2=m2 for some positive integer m. The value of x + y + m is.
154
x→ab or x=10a+b
y→ba or y=10b+a
Now x2−y2=(10a+b)2−(10b+a)2
=99(a2−b2)
=32×11(a+b)(a−b) ------ (1)
According of Q
(a+b)(a−b)=11anda−b=1
⇒a+b=11anda−b=1
⇒a=6,b=5
Hence
x=65
y=56
and m=33
⇒x+y+m=154