Question

What is the solution of the equation x2 + 8x + 5 = 0?

Answer 1

x = -0.683 (3dp)

x = -7.317 (3dp)

Explanation:

Step 1: Apply the quadratic formula

(-b±(
`\sqrt{b^(2)-4ac}`)) / 2a

a = 1 (x²)

b = 8 (8x)

c = 5 (5)

(-8±(
`\sqrt{8^(2)-4 x 1 x 5}`)) / 2 x 1

Step 2: Simplify

(-8±(
`√(44)`)) / 2

Step 3: Solve

You need to replace the ± with first a + and then a -.

(-8+(
`√(44)`)) / 2 = -0.683 (3dp) = x

(-8-(
`√(44)`)) / 2 = -7.317 (3dp) = x

Hope this helps!