Question

medal given for help
r2-8r-20
can you show me how to break it down to show the work
it say factor the expression ..show all work-

Answer 1

\[r^2-8r-20\]

To factor this, multiply the coefficient of the first term by the coefficient of the last term:
1*-20 = -20

Now, find a pair of factors of -20 that add to the coefficient of the middle term, -8

What are two numbers that multiply together to give you -20, and add together to give you -8?

Answer 2

ok (r2-10r+2r-20)
(r(r-10+2r-20)
(r2-10r+2r-20)
(r+2)(r-10))
is this the correct breakdown?

Answer 3

Answe (r+2)(r-10)

Answer 4

Yes, that is, although you've got some extra and/or missing parentheses in a few spots.

Factors obviously are -10, 2:
\[r^2 - 10r + 2r -20\]\[(r^2-10r) + (2r-20)\]\[r(r-10) + 2(r-10)\]\[(r-10)(r+2)\]

checking our work:

\[(r-10)(r+2) = r(r+2)-10(r+2) = r^2 + 2r - 10r -20 = r^2-8r -20\checkmark\]

Answer 5

TY

Answer 6

Can you check this one -Did I break it down right?
8x4=36x3
4x3(2x)+4x3(-9)
4x3(2x-9)

Answer 7

Assuming that your first line is supposed to be \(8x^4-36x^3\) then you did it correctly

\(4x^3(2x-9)=2*4*x^3*x-9*4x^3 = 8x^4-36x^3\)

Answer 8

have to put = in front of each breakdown ?

Answer 9

No was just doing all the work on one line...

\[4x^3(2x-9) = 2x*4x^3 - 9*4x^3\]\[2x*4x^3-9*4x^3 = 8x^4-36x^3\]
same thing, but more wear and tear on my fingers and keyboard :-)

Answer 10

ty

Answer 11

you're welcome!