SOLUTION: i need to find the value of "y" in the equation 6y+2=2y*y-6. i forgot how to remove the y*y (y squared)and solve.

Algebra ->  Equations -> SOLUTION: i need to find the value of "y" in the equation 6y+2=2y*y-6. i forgot how to remove the y*y (y squared)and solve.      Log On


   

Question 247449: i need to find the value of "y" in the equation 6y+2=2y*y-6. i forgot how to remove the y*y (y squared)and solve.
Found 2 solutions by oberobic, checkley77:
Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
6y+%2B+2+=+2y%5E2+-+6
Subtract 2 from both sides
6y+=+2y%5E2+-+8
Subtract 6y from both sides
0+=+2y%5E2+-+6y+-+8
Divide both sides by 2
0+=+y%5E2+-+3y+-+4
Which means
y%5E2+-+3y+-+4+=+0
Can you factor -4 to find two factors that total -3?
How about -4 and + 1?
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%28y-4%29%28y%2B1%29=0
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So, y = 4 or -1.
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Always check your work!
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Substitute y =4.
6y+%2B+2+=+2y%5E2+-+6
6%284%29+%2B+2+=+2%284%5E2%29+-+6
24+%2B+2+=+2%2816%29+-+6
26+=+26
So y =4 checks.
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Substitute y=-1.
6%28-1%29+%2B+2+=+2%28-1%5E2%29+-+6
-6+%2B+2+=+2%281%29+-+6
-4+=+-4
So y = -1 checks.
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Done.

Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
6y+2=2y*y-6.
6Y+2=2Y^2-6
Y^2-6Y-6-2=0
Y^2-6Y-8=0
Y+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
Y=(6+-SQRT[-6^2-4*1*-8])/2*1
Y=(6+-SQRT[36+32])/2
Y=(6+-SQRT68)/2
Y=(6+-8.246)/2
Y=(6+8.246)/2
Y=14.246/2
Y=7.123 ANS.
Y=(6-8.246)/2
Y=-2.246/2
Y=-1.123 ANS.