Question

Find the solution(s) of the system of equations. x2 + y2 = 18 y = x + 6

Answer 1

Answer:

(-3,3)

Step-by-step 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