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Im really bad at this, please show me and explain all the steps to get the answer. thanks!!!!!!!!!!!

2007-08-25 17:29:41 · 7 answers · asked by shawna 2 in Science & Mathematics Mathematics

7 answers

Assuming question is meant to be:-
4(y - 7) - 2y(y - 3) = 6y²
4y - 28 - 2y² + 6y = 6y²
8y² - 10y + 28 = 0
4y² - 5y + 14 =0
y = [ 5 ± √(25 - 224) ] / 8
y = [ 5 ± √(- 199) ] / 8
y = [ 5 ± i √(199) ] / 8

2007-08-26 09:42:01 · answer #1 · answered by Como 7 · 1 0

4(y - 7) - 2y(1 - 3) = 6y² >>>Expand the bracket
4y - 28 - 2y + 6 - 6y² = 0
-6y² + 4y - 2y - 28 + 6 = 0
-6y² + 2y - 22 = 0 >>>Make in general form
You can using completing the square or quadratic formula. You can't using trinomial method or cross multiplication method because the solution cannot be determined.

Completing the square
-6y² + 2y - 22 = 0
-6y² + 2y = 22 >>>Rearrange in the form x² + px = q
-6y² + 2y + (2 / 2)² = 22 + (2 / 2)² >>>Add (coefficient of x / 2)² to both side. Coefficient of x is q which is 2.
-6y² + 2y + 1² = 22 + 1²
(-6y + 1)² = 22
√(-6y + 1)² = √22
-6y + 1 = √22
-6y = -1 ± √22

-6y = -1 + √22
-6y = 3.690
y = 3.690 / -6
y = -0.615 >>>3 decimal point

-6y = -1 - √22
-6y = -5.690
y = -5.690 / -6
y = 0.948 >>>3 decimal point

Thus y = -0.615 or y = 0.948

2007-08-25 17:58:27 · answer #2 · answered by Anonymous · 1 1

open the brackets

4y -28 -2y +6y -6y^2 = 6y^2

8y -28 = 6y^2

bringing 6y^2 to other side
6y^2 - 8y + 28=0
divide the equation by 2
3y^2 -4y +14 =0

use the discriminant formula

and get the final answer it will have imaginary roots

2007-08-25 17:49:40 · answer #3 · answered by mubaris h 3 · 0 0

if you simplify that it gets to

6y^2 + 4y + 28 = 0

and divide both sides by 2 to get

3y^2 + 2y + 14 = 0

and use the quadratic formula to get the value of y

but i think that leaves you with an imaginary answer

2007-08-25 17:46:53 · answer #4 · answered by Jay 4 · 0 0

4(y-7)-2y(1-3)=6y^2
4y-28-2y(-2)=6y^2
6y^2-8y+28=0
3y^2-4y+14=0
delta=(16-4*3*14)^.5<0
then
this equation has not real answer.

2007-08-25 17:49:59 · answer #5 · answered by hamid b 2 · 0 0

ஐClueLessஐ

I Hate Math, Sorry I Couldn't Help You!
Good Luck!

2007-08-25 17:34:16 · answer #6 · answered by Suɱɱeʁ 0ɟ 69 5 · 0 2

Do some multiplying...maybe some division...possibly some subtraction and THERE YA GO.

2007-08-25 17:36:13 · answer #7 · answered by Anonymous · 0 2

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