x = one number
2450  x = other number ← their sum is 2450
2450  x = x² ← one number equals square of another
x² + x  2450 = 0 ← subtracted 2450 and added x
(x + 50)(x  49) = 0 ← factored
x + 50 = 0 or x  49 = 0 ← set equal to zero
x = 50 or x = 49 ← solved
2450  x = 2401 ← substituted
49 and 2401 are the two numbers
 Proof
