Answer:
x² + y² = 13 ---1
y = x + 1 ---2
First make one of the unknowns the subject so you can substitute it into the other equation. Since 2 already has y as the subject, we can substitute 2 into 1 to find x.
Substitute 2 into 1:
x² + (x +1)² = 13
x² + (x² + 2x + 1) = 13
2x² + 2x - 12 = 0
2 is a common factor so we factorize it out.
2(x² + x - 6) = 0
x² + x - 6 = 0
Factorize the equation further.
(x - 2)(x + 3) = 0
x - 2 = 0 or x + 3 = 0
x = 2 or x = - 3
Substitute values of x into 2 to find y.
y = 2 + 1 or y = - 3 + 1
= 3 = - 2
Hence, x = 2 and y = 3 or x = - 3 and y = - 2.