Question

Solve. x2 + 8x + 25 = 0

Answer 1

Do the Completing the Square method! :) it's pretty easy
First you subtract 25 from both sides to get the numbers with variables by themselves.

Answer 2

x2 + 8x = -25

Answer 3

Then you divide 8 by 2 to get 4. Then you have to square 4.
You get 16 and you have to add 16 to both sides to equal out the equation.

Answer 4

x2 + 8x + 16 = -25 + 16
Simplify.
x2 + 8x + 16 = -9

Answer 5

It's asking for these answers

–4 ± i

–3 ± 4i

–4 ± 3i

–2 ± 4i

Answer 6

Now factor the trinomial into a binomial.
(x + 4)2 = -9
Then you have to find the square root of these.
you end up with x + 4 = √-9
That's where the imaginary number part comes in.

Answer 7

√-9 becomes 3i.
x + 4 = 3i then you just simplify that

Answer 8

so
x = -4 + 3i

Answer 9

Plus or minus.

Answer 10

So it's the third one.

Answer 11

Thanks so much!

Answer 12

You're welcome!