2x^2-16x-18

Question

PLEASE HELP ME TO FIND THE ANSWER OF THE FACTORISATION QUESTION GIVEN ABOVE,2x^2-16x-18,PLEASE ANSWER THE QUESTION AS SOON AS POSSIBLE ,STEP BY STEP.

Answer 1

You can start by dividing the entire polynomial by two to reduce terms.

(2x²-16x-18)/2 = x²-8x-9

Now you have to find two roots whose sum is equal to -8 and whose product is equal to -9. The negative product means that they will have opposite signs. Since the factors of nine are 1,3, and 9, the answer should be obvious: +1 and -9

(x-9)(x+1) is your answer

If you look at any factorization problem in its most generic form the answer to

ax²+bx + c will have two roots (sometimes a double root, and provided it has a solution)

so that if you started from:

(x+r₁)(x+r₂) and multiply it out you would get

x²+ r₁x + r₂x + (r₁*r₂) = x² + (r₁+r₂)x + (r₁*r₂)

where a =1

b = (r₁+r₂)

 c = (r₁*r₂)