Question

What this solving system of equations?
x+y=-3
y=x^2+4x+1

Answer 1

x = -4, y = 1

x = -1, y = -2

Explanation:

(1) x + y = -3 (2) y =
`x^(2) +4x + 1`

y = -x - 3 -x - 3 =
`x^(2) +4x + 1`

`x^(2) + 5x + 4 = 0\\`

(x + 4)(x + 1) = 0

x = -4 or x = -1

y = -(-4) - 3 = 4 - 3 = 1

y = -(-1) - 3 = 1 - 3 = -2

Answer 2

Explanation:

y = -x-3

y = x^2 + 4x + 1

x^2 + 4x + 1 = -x-3

x^2 + 5x + 4 = 0

Quadratic Formula

x = [-5±√(5²-4⋅1⋅4)]/[2⋅1] = [-5±√9]/2 = [-5±3]/2 = 1,-4

(x,y) = (1,-4) of(-4,1)