how would u solve this using the quadratic formula or complete the square.

7x^3 + 12x – 3 = 0

ya thats what i thought

February 2nd, 2011 @12:49 pm

X= -b+or- the square root of b squared minus 4ac over 2a

February 2nd, 2011 @12:55 pm

You can’t use the quadratic formula/completeing the square/factoring/graphic, because it’s not a quadratic. A quadratic’s highest exponent is 2. Therefore, this equation is a not a quadratic, it’s a cubic.

February 2nd, 2011 @1:46 pm

7x^2 + 12x – 3 = 0 I think you mean this??

a = 7

b = 12

c = -3

-12+- the squrt of (12^2 – 4(7)(-3) / 2(7)

-12 plus/minus the squrt of 144 + 84 / 14

-12 plus/minus the sqrt of 288/14

-12 + 15.10 / 14

x= 0.2214

AND

-12 – 15.10/14

x = -1.936

February 2nd, 2011 @1:56 pm

In this case, the formula is a bit more complex…

highest power must be 2