Question

Solve by completing the square: x^2 - 2x - 24 = 0
A. -4, -6
B. -4, 6
C. 4, -6
D. 4, 6

Answer 1

start by adding 24 both sides

Answer 2

x^2 - 2x - 24 = 0
+24 +24

x^2-2x = 24

Answer 3

x^2-2(1)x = 24

add 1^2 both sides

x^2-2(1)x + 1^2 = 24 + 1^2

Answer 4

Now stare at the left hand side, can does it look like a perfect square ?

Answer 5

Yes.

Answer 6

good :) write it as a square :-

\(a^2-2ab + b^1 = (a-b)^2\)

Answer 7

x^2-2(1)x + 1^2 = 24 + 1^2

(x-1)^2 = 25

take sqrt both sides

Answer 8

wat do you get ?

Answer 9

I don't know where to go from there.

Answer 10

its okay :)
its easy actually, once u see it done, u wil get it

Answer 11

\(\large (x-1)^2 = 25\)

take sqrt both sides

\(\large \sqrt{(x-1)^2} = \sqrt{25}\)

Answer 12

square, and sqrt cancel out on left side

Answer 13

\(\large \sqrt{(x-1)^2} = \sqrt{25}\)

\(\large x-1 = \pm 5\)

that gives,

\(\large x-1 = + 5 \) (or) \(\large x-1 = -5\)

\(\large x = 6 \) (or) \(\large x = -4\)

Answer 14

check if my calculations were correct...

Answer 15

Okay. I will look through this. Thank you.

Answer 16

np :)