Use synthetic division to divide the following problems.
(x2 + 13x + 40) ÷ (x + 8)

Question

Use synthetic division to divide the following problems. 
    (x2 + 13x + 40) ÷ (x + 8)

anonymous · Answer

Please help!!!!!

anonymous · Answer

it is almost impossible to write division here 
start with the coefficients

anonymous · Answer

1      13     40

anonymous · Answer

then put a $-8$ on the side 

        1      13     40
-8
________________

anonymous · Answer

bring down the 1 

        1      13     40
-8
_______________
       1

anonymous · Answer

$-8\times 1=-8$
        1      13     40
-8              -8
_______________
       1

anonymous · Answer

add 

        1      13     40
-8              -8
_______________
       1        5

anonymous · Answer

-8*5=-40

        1      13     40
-8              -8     -40
_______________
       1        5

anonymous · Answer

add 

        1      13     40
-8              -8     -40
_______________
       1        5       0

anonymous · Answer

so there is no remainder and 
$$x^2+8x+40=(x+8)(x+5)$$ which you probably could have figured out in ten seconds without division

anonymous · Answer

oops typo there
i meant 
$$x^2+13x+40=(x+8)(x+5)$$

anonymous · Answer

thank you! would you be able to help me with one more? just to get me started because I think I got most of it. @satellite73

anonymous · Answer

k

anonymous · Answer

Let f(x) = 4x3 + 7x2 – 13x – 3 and g(x) = x + 3. Find f of x over g of x

anonymous · Answer

$$\frac{f(x)}{g(x)}=\frac{4x^3+7x^2-13x-3}{x+3}$$ is a start
now you can divide as before if you need to

anonymous · Answer

this time you will get a quotient and a remainder, since $x+3$  does not divide evenly

solomonzelman · Answer

I totally agree with one of satelline's posts, why synthetic division when you can just factor ?

anonymous · Answer

wanna use synthetic division for this one?

anonymous · Answer

yes, please im supposed to for my assignment.

anonymous · Answer

same as before
list the coefficients 

      4      7       -13       3
-3
____________________

anonymous · Answer

bring down the 4

      4      7       -13       3
-3
____________________
       4

anonymous · Answer

muliply -3*4=-12
      4      7       -13       3
-3         -12
____________________
       4

anonymous · Answer

add
      4      7       -13       3
-3         -12
____________________
       4     -5

anonymous · Answer

-3*-5=20
      4      7       -13       3
-3         -12      20
____________________
       4     -5

anonymous · Answer

damn arithmetic mistake!

anonymous · Answer

-3*-5=15!!
      4      7       -13       3
-3         -12      15
____________________
       4     -5       2

anonymous · Answer

i see i made another mistake, the last number is $-3$ not $3$ so final answer is 
$$4x^2-5x-7-\frac{9}{x+3}$$

anonymous · Answer

wait you lost me. where did the 20 come from?

anonymous · Answer

that was a total mistake
that is why i changed it to 15

anonymous · Answer

oh okay sorry

anonymous · Answer

there, just got rid of the mistake one and left the correct one up

anonymous · Answer

okay! again thank you so much!!