Question

2x^2+4x=16
x=?

Answer 1

Rearrange it to become

2x^2+4x - 16 = 0

Then plug it into the formula or factor it

Answer 2

You can factor out a 2, see where that gets you..

Answer 3

Do you get it?

Answer 4

no,I don't

Answer 5

it becomes
2(x^2 + 2x - 8) = 0
when you factor it

Answer 6

Can you factor x^2 + 2x - 8 ?

Answer 7

okay let me try this

Answer 8

it would be (x+4)(x-2) right?

Answer 9

Do you know the formula? The quadratic formula?

Answer 10

Yes and no, I forgot the steps

Answer 11

Nice you factored it right

Answer 12

So then I would plug the x+4 and x-2 into the equation right,? it would be 2(4)^2+4(-2)=16??

Answer 13

So
2(x^2 + 2x - 8) = 0

2 (x - 2 ) ( x + 4 ) = 0


NOW, you know how anything times zero = 0?

You have to make at least one of the brackets = 0 to get zero as an overall answer. So what can we put as x to make the brackets zero? There is x in two places so there are 2 answers

Answer 14

To find the answers, factoring is one way. The formula is another. Yo chose to factor so you dont need to use the formula anymore

Answer 15

2x-2=0 and 2x+4=0

Answer 16

You just have to make the brackets = 0, don't put in the two!

See we got
2 (x - 2 ) ( x + 4 ) = 0


So, one bracket is

(x-2) . We want to make this = 0

x-2 = 0
x = 2 !!! One of the answers..


Next bracket

(x+4)
Make it equal to zero.
x+4 = 0
x= -4

So the answer is x = -4 or x = 2

Answer 17

oh wow, that was really simple, Now I under stand

Answer 18

Yay!! :)

Answer 19

Thank u

Answer 20

you're welcome