3x^2-18x-36

Question

3x²-18x-36

Answer 1

What are you attempting to do?  You have listed an equation but not told us what you are attempting to do with it...

 

3x²- 18x - 36

We can factor a 3 out since it is a factor of all the coefficients and the constant

 

3(x² - 6x - 12)

 

There are no factors of -12 that add to -6 so the polynomial is not further factorable...

 

We have a quadratic equation here if you are trying to solve for

 3x²- 18x - 36 = 0   we can use the quadratic equation to do that

 

3(x² - 6x - 12)= 0

Divide both sides by 3

x² - 6x - 12 = 0

 

a = 1, b = -6, c = -12 ...  x = -b/2a ± [√(b²-4ac)]/2a

 

x = 6/2 ±[√[(-6)²-4(1)(-12)]]/2

 

x = 3 ±[√(36 + 48)]/2

x = 3 ±(√84)/2

x = 3 ±[√[(4)(21)]]/2

x = 3 ± (2√21)/2

x = 3 ±√21