Answer:
(-3,3)
Explanation:
x² + y² = 18
y = x + 6
(Assuming you mean x and y to the power of 2. Use the ^ symbol to tell that is it an exponent like this: x^2)
First, substitute the y in the first equation
x² + (x + 6)² = 18
FOIL
x² + x² + 12x + 36 = 18
2x² + 12x + 36 = 18
Subtract 18 from both sides
2x² + 12x + 36 = 18
- 18 - 18
2x² + 12x + 18 = 0
Divide both sides by 2
(2x² + 12x + 18)/2 = 0/2
x² + 6x + 9 = 0
Factor
(x + 3)(x + 3) = 0
x has to be -3 for the equation to be 0, so the x = -3
Plug the new x into one of the original equations; we'll use the second one
y = -3 + 6
y = 3