+48 How many different triples (a,b,c) from the set {1,2,3,4,5} satisfy the equation a^2 + bc = b^2 + ac ?
Work:
a^2 + bc = b^2 + ac
0 = b^2 + s^2 + ac + bc
2ba = c(b+a) + (b^2 + 2ba + a^2)
2ba = (b+a) (b+a) + c (a+b)
2ba = (b+a+c) (b+a)
How do I go from here?
