Question

an you please show me how to solve an equation like this?! It's not making sense. x² + 6x = –5

Answer 1

Add the 5 and set your polynomial to zero.

Answer 2

x² + 6x + 5 = 0?

Answer 3

\[x^2+6x+5 =0\]
notice that it's in the form: \[ax^2+bx+c\]
to factor, you must find TWO numbers whose product is "c", but the sum of the two terms, result in "b". Does that make sense?

It means: n x n = c, but n + n = b

Answer 4

where the n's are two constants. meaning numbers - obviously.

Answer 5

Um...still don't get it.

Answer 6

you have to find two numbers whose product is 5 and sum is 6

Answer 7

Oh! Okay!

Answer 8

Yes.

Answer 9

But...that's for factoring right? I need to find the value of x...

Answer 10

yea, you can solve for x by factoring

Answer 11

Yes, to find the value(s) of "x". You need to factor.

Answer 12

or you can use the quadratics formula

Answer 13

Okay...

Answer 14

quadratic formula usually makes the algebra more tedious. It's best if you factor.

Answer 15

Can you guys check my answer once I attempt to figure it out?

Answer 16

sure

Answer 17

Of course.

Answer 18

Okay, I'm coming up with jibberish. Could you walk me through it?

Answer 19

make a list of factors of 5

Answer 20

just 1 and 5

Answer 21

and -1 and -5

Answer 22

yes. so (x + 1)(x + 5) = 0

now you can set those two factors (x + 1 and x + 5) set to 0 and solve for x

Answer 23

right, but you couldn't use -1 and -5 because those don't add up to 6

Answer 24

okay

Answer 25

so solve for x in both

x + 5 = 0 and x + 1 = 0

and they will be your answers

Answer 26

-5 and -1?

Answer 27

yes :]

Answer 28

okay thanks!

Answer 29

no problem