How do you factor x2 - 6x - 16?

Answer 1

20

Answer 2

Since there is an x2, we can do this step first:

(x )(x )

For this question, we need to use the quadratic formula:

-b±√(b2-4ac)

-----------------

2a

Let me explain some of the symbols and letters first.

±- is the plus or minus sign. You will perform both separately when we reach this step.

√-is the square root sign.

The line above 2a is the division line.

The letter a represents the quantity of x2, which is 1 in this case

The letter b represents the quantity of x, which is 9 in this case

The letter c represents the quantity of 1, which is 16 in this case

Let's plug the numbers in, so your formula will look like this:

-9±√(92-4(1)(16))

-----------------

2(1)

Simplify:

-9±√((81)-(64))

----------------- =

2

-9±√(17)

----------------- =

2

-9±(4.1231)

----------------- =This is the part where we split off into plus or minus

2

-9+4.1231

----------------- =

2

-4.8769

----------------- =

2

-2.4384 (This is one part of your answers. Let's do the minus part now.)

-9-4.1231

----------------- =

2

-13.1231

----------------- =

2

-6.56155 (This is your second part of your answer. The factorization is below)

(x-2.4384)(x-6.56155)

Answer 3

That doesn't factor neatly. Applying the quadratic formula, we find two real solutions: -8 plus or minus 2 times the square root of 14.

x = -0.5166852264521173

x = -15.483314773547882

Answer 4

16 - x2 would be factored into (4-x) and (4+x)

To double-check, multiply the factors:

(4-x)(4+x) = 16 + 4x - 4x -x2 = 16 - x2

Answer 5

4x - 16 = 4 (x - 4)

Factor out the greatest common factor (GCF), which is 4, and divide 4x - 16 by 4 to get x - 4, making the answer 4 (x - 4).

Answer 6

There is a formula for the "difference of squares." In this case, the answer is

(4x + 1)(4x - 1)

Answer 7

x2 - 16 + 64 = x2 + 48, which does not have real factors.

Answer 8

(3x + 4)(3x - 4)

Answer 9

(X-2) (X+8)

FOIL and see.

Answer 10

(x - 8)(x - 8)