Question

You must show your work on each of the following questions.

Solve 5x2 = –45x.

Answer 1

\[5x^2 = –45x\]Add 45x to both sides\[5x^2+45x=0\]Factorize the expression. Can you do it?

Answer 2

But there's only 1.

Answer 3

no im lost by the factoring part

Answer 4

Example:
\[2a^3 - 2a\]1. factor by grouping\[=2a(a^2-1)\]2. use the identity a^2-b^2 = (a+b)(a-b)\[=2a(a-1)(a+1)\]
It's your turn to try. Factorize \(5x^2 +45x\)

Answer 5

5x2+45x = 5x(x5-1) am i getting it so far?

Answer 6

?? @callistro

Answer 7

What are you doing lol ?

Answer 8

\(\Huge\text{Lolwut.}\)

Answer 9

i need to solve for 5x2 = –45x.

Answer 10

Nope.
\[5x^2+45x = 5(x)(x) + 5(9)(x)\]What are the common factors of these two terms?

Answer 11

not sure

Answer 12

What are common there? :S

Answer 13

\[\Huge{x}.\]

Answer 14

Lets see it like this

5x^2+45x=0

Now we have to take common you took the common right there which was 5x but you did not leave the rest right.

Now try taking common again out of it.

Answer 15

you mean take it out??

Answer 16

Yeah Right @daze

I know you can do it.

Answer 17

Well if you do not understand this,

we can use another method ?

Answer 18

@daze Please respond.

Answer 19

\(\Huge\text{that'd help.}\)

Answer 20

well yea could we use another method please

Answer 21

\(\huge\text{there we go.}\)

Answer 22

Well there are two more methods :

One of them is using the quad equation

\[x=\frac{ -b \pm \sqrt{b^2-4ac} }{ 2a }\]


Well just compare its general form with your question,

Which is,

\[ax^2+bx+c=0\]

You can now solve it i guess.

Answer 23

5x^2+45x=0

Try to simplify your equation first by taking 5 common

5(x^2+9x)=0

x^2+9x+0=0

where

a=1,b=9 and c=0


Now put it in quad equation.

Answer 24

@daze Now please solve it.