Question

6y^2-24y=0 help solve with a little explanation plzz :0

Answer 1

elekt u posted but it disappeared -_-

Answer 2

Factor out the y \[y^2-24y=\]
\[y(6y-24)=0\]

Answer 3

okay i understand so far

Answer 4

Ah, I always mess up with writing equations in here. Anyway, so y = 0 or y = 4

Answer 5

okay im not following how you got the solution from y(6y-24)=0

Answer 6

You just factor out the y, because it is a common factor in the expression.

Answer 7

Try mulitplying the expression y(6y-24) to get back 6y^2-24y again

Answer 8

yes i get that but how do you get to the sol. set (0,4)

Answer 9

to get the solutions it to equal 0

either y=0
or 6y-24=0
y=4 in that case.

Following on from Elekt original message

Answer 10

Thanks Maclntosh :)

Answer 11

how do you get y=4?

Answer 12

You see that, in order for the expression to equal zero, once factored, either y must equal zero or the parantheses must equal zero. Multiplying by zero always gives zero, remember :)

Answer 13

y=4 you get from solving 6y-24 = 0 like this
6y = 24
y = 24/6 = 4

Answer 14

Complete solution:
\[6y^2-24y= 0 \]
\[y(6y-24)=0\]
In order for this to happen \[y=0\] or \[6y-24 = 0\]
\[6y =24\]
\[y = \frac{24}{6} = 4\]

Answer 15

6y-24=0 <-- thats after we factored out a y, right? so where did the y go?

Answer 16

i get now, how to get y=4 but theres a lost y :(

Answer 17

No, the factored y is already accounted for because it must equal 0 in order for the equation to be satisfied. If it is not zero, well then y = 4 because of the above.

Answer 18

so once its factored out its gone for good? ;p i kinda get it i guess

Answer 19

No, not at all. We just see that the equation y(6y-24=0 must have either what is outside the parantheses, that is y, equal to zero, or the inside of the parantheses, that is 6y-24, equal to zero for the equation to be satisfied.

Answer 20

okay now that the y=4 is understood can you help with how you got the y=0?

Answer 21

ohhh wow.. gotcha

Answer 22

Thus y must equal either 0 or 4 for this to hold :)

Answer 23

okayy. this is so confusing and i have a test on this thur! what should i do to practice and learn this betterr?

Answer 24

Understand it.

Answer 25

okay! so lets to this prob.. ill tell u what i think i should do..

Answer 26

x^2=-49

Answer 27

This won't work, because something squared is never negative (when you work with real numbers anyway. Square roots can be defined for negative numbers in something called the complex plane of numbers, but that is far above your head at the moment).

Answer 28

x=-7i or 7i

Answer 29

We're working on basic algebra here, introducing complex numbers will just confuse things.

Answer 30

no im suppose to use imaginary numbers!

Answer 31

Oh, u are?

Answer 32

no this is from complex ch

Answer 33

yes

Answer 34

Well, than I am sorry to assume you were not working with that *flush*

Answer 35

its okay!
so help explain how kavu got his answer
\

Answer 36

x^2=-49
x^2=√(7)^2√(-1) or x^2=√(-7)^2√(-1)
x=7i or x=-7i