algebra help?

Question

I need to solve the equation y^2 -6y + 8 = 0 can anyone help?

Answer 1

y² - 6y + 8 = 0

The middle term is - 6y

Find the sum of the middle term

y² = 1

multiply the first term 1 times the last term 8 equals 8 and factor.

factors of 8

1 x 8
2 x 4. . . .<=. .use these factors

- 4 and - 2 satisft the sum of the middle term

insert - 4x and - 2x into the equation

y² - 6y + 8 = 0

y² - 4x - 2x + 8 = 0

y(y - 4) - 2(y - 4) = 0

(y - 2)(y - 4) = 0

- - - - - - - - -

Roots

y - 2 = 0

y - 2 + 2 = 0 + 2

y = 2

- - - - - - -

Roots

y - 4 = 0

y - 4 + 4 = 0 + 4

y = 4

- - - - - - - - s--

Answer 2

you factor it. Y^2 - 6Y+ 8=0 factored is (Y-2)(Y-6)=0 so to make the first half equal 0 you have to make one of the parinthases equal zero since they're being multiplied together. So, Y=2 and 6

If it's factoring you're having trouble with, just look at the first and last numbers. Forget the middle one for now... find all the different combinations there are for multiplying two numbers together and getting 8: 1X7 , 2X4, -1X-7, -2X-4. When you FOIL (that's what all my teachers called it... I don't know if yours do, but it stands for firsts outsides insides last and it's the order in which you multiply to undo the factoring) the middle number in the equation you're trying to solve (-6) is the sum of the two numbers that you use to get 8 (unless there's another number in front of the first numer), so if you go back to the different combinations above, the only one that would add up to -6 is -2 and -4 so the answer has to be (y-2)(y-4)... It's a lot easier than I make it sound. Practice makes perfect. Good luck and I hope that helped.

Answer 3

the trick - instead of calling the unknown x its called y

this one will factor into (y-4)(y-2)=y^2-4y-2y+8=y^-6y+8=0
so either y-4=0 or y-2=0 hence y=4 is a root or y=2 is a root

other way recognize that this is a quadratic, a=1, b=-6, c=8 and use the formulae

Answer 4

y^2-6y+8=0
(y-4)(y-2)=0
y-4=0 ; y-2=0
therefore:
y=4 and y=2
check:
4^2-6(4)+8=0 : correct
2^2-6(2)+8=0 : correct

Answer 5

Hey, that's a COOL name you got!!

Anyhow, here it is...

y=4 will give you

(4x4) - (6x4) + 8 = 0
16 - 24 + 8 = 0
-8 + 8 = 0
so 0=0

See ya!

Answer 6

y^2-6y+8=0
y^2-4y-2y+8=0
(y-4)(y-2)
y=4or2

Answer 7

teh factors are (y-2)(y-4) = 0

There fore y = 2 and y = 4

Answer 8

use the quadratic formula, which can be found at:
http://www.atlanticwinds.com/mathmem/quadratic_formula.gif

so...

(--6 +/- sqrt((-6)^2-4*1*8))/(2*1)=y
3 +/- 1 =y
y=2 or 4