SOLUTION: Please help me solve this equation: 3x^2 - 2x = 12.

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Question 242990: Please help me solve this equation: 3x^2 - 2x = 12.
Found 2 solutions by josmiceli, unlockmath:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
3x%5E2+-+2x+=+12
Subtract 12 from both sides
3x%5E2+-+2x+-+12+=+0
Now this is in the general form
ax%5E2+%2B+bx+%2B+c+=+0
Now apply the quadratic formula
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
where
a+=+3
b+=+-2
c+=+-12
x+=+%28-%28-2%29+%2B-+sqrt%28+%28-2%29%5E2-4%2A3%2A%28-12%29+%29%29%2F%282%2A3%29+
x+=+%28+2+%2B-+sqrt%28+4+%2B+144+%29%29%2F+6+
x+=+%28+2+%2B-+2%2Asqrt%28+37+%29%29%2F+6+
x+=+%28+1+%2B-+sqrt%28+37+%29%29%2F+3+
The answers are:
x+=+%281+%2B+sqrt%2837%29%29%2F3
and
x+=+%281+-+sqrt%2837%29%29%2F3
It's a difficult process, but you can plug
these answers (one at a time) back into the
original equation and see if they work

Answer by unlockmath(1688) About Me  (Show Source):
You can put this solution on YOUR website!
Hello,
Let's first get this equation to equal zero.
3x^2 - 2x -12 = 0
The way to solve this is with the quadratic formula which will look like:
{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }
Now plug in the values will be:
{x = (-(-2)b +- sqrt( 4-4*3*(-12) ))/(2*3) }Do the calculations:
{x = (2 +- sqrt( 148 ))/(6) } Now sq root 148
{x = (2 +- 12.17/6 } So we have 2 answers
x= 2.36 (Rounded off)
x= -1.695
Check these out by using the answer in the original equation.
RJ Toftness
Check out my book at www.math-unlock.com