Solve the equation by completing the square.

x squared plus 9 x minus 14 equals 0
(1 point)
Responses

10.35, 1.35
10.35, 1.35

10.35, negative 1 point 35
10.35, Image with alt text: negative 1 point 35

negative 10.35, negative 1.35
Image with alt text: negative 10.35, negative 1.35

negative 10.35, 1.35
Image with alt text: negative 10.35 , 1.35

1 answer

To solve the equation x^2 + 9x - 14 = 0 by completing the square, we first need to move the constant term to the other side:

x^2 + 9x = 14

Next, we need to find the value that completes the square. This value is calculated by taking half of the coefficient of x (which is 9 in this case) and squaring it:

(9/2)^2 = 81/4

Now we add and subtract this value inside the parentheses:

x^2 + 9x + 81/4 = 14 + 81/4
x^2 + 9x + 81/4 = 56/4 + 81/4
x^2 + 9x + 81/4 = 137/4

The left side of the equation can now be written as a square:

(x + 9/2)^2 = 137/4

Taking the square root of both sides gives:

x + 9/2 = ±√(137/4)
x + 9/2 = ±√137 / 2
x = -9/2 ± √137 / 2

Therefore, the solutions are x = -9/2 + √137 / 2, x = -9/2 - √137 / 2, which in decimal form are approximately:

10.35, -1.35