Use synthetic division to find P(3) for P(x) = x4 – 6x3 – 4x2 – 6x – 2.

a. 3
b. –137
c. 299
d. –47

Question

Use synthetic division to find P(3) for P(x) = x4 – 6x3 – 4x2 – 6x – 2.  

    a. 3
    b. –137
    c. 299
    d. –47

amistre64 · Answer

are all your powers accounted for?

amistre64 · Answer

hmm, theres a simpler way;  do you have to show your work?

anonymous · Answer

Lemmme try one :)

amistre64 · Answer

give it a shot :)

anonymous · Answer

ALRIGHTY! :)

anonymous · Answer

no you dont have to show my work

unklerhaukus · Answer

im not sure how to use Use synthetic division here

amistre64 · Answer

$$3^3*3~<~3^3(-6)$$so the answer at least will be negative

amistre64 · Answer

the remainder of the synthetic is the same as the value of the poly

unklerhaukus · Answer

oh the remainder

anonymous · Answer

so its 3?

amistre64 · Answer

3 is not a negative value .....

amistre64 · Answer

x4 – 6x3 – 4x2 – 6x – 2
     0                                     <-- add this row
   ----------------------
3 )                                  [R]  <-- multiply this row

amistre64 · Answer

how you coming along with it Zofia?

anonymous · Answer

Eh.. Not getting it lol

amistre64 · Answer

x4 – 6x3 – 4x2 – 6x – 2
     0                                     <-- add this row
   ----------------------
3 )  1                               [R]  <-- multiply this row 





      x4 – 6x3 – 4x2 – 6x – 2
     0      3                              <-- add this row
   ----------------------
3 )  1                              [R]  <-- multiply this row 





      x4 – 6x3 – 4x2 – 6x – 2
     0      3                            <-- add this row
   ----------------------
3 )  1   -3                       [R]  <-- multiply this row 





      x4 – 6x3 – 4x2 – 6x – 2
     0      3     - 9                   <-- add this row
   ----------------------
3 )  1   -3                       [R]  <-- multiply this row 





      x4 – 6x3 – 4x2 – 6x – 2
     0      3     - 9                   <-- add this row
   ----------------------
3 )  1   -3    -13              [R]  <-- multiply this row 




etc ...........................

anonymous · Answer

Im still lost I reallly dont get synthetic division

amistre64 · Answer

then ask me questions about my method so i can see what your confusion might be

amistre64 · Answer

and, if you really dont get synthD, and you dont have to show your work; then just solve the equation for x=3

anonymous · Answer

ok thank you.

amistre64 · Answer

good luck :)

I have yet to come across a specific need for synthD; so far it just exists as a different method that might make life easier in some cases.  So its good to have in your quiver.

anonymous · Answer

@amistre64 Is it -47 im solving the problem right now

amistre64 · Answer

maybe ....

      x4 – 6x3 – 4x2 – 6x  – 2
     0      3     - 9    -39  -135
   ------------------------
3 )  1   -3    -13    -45     my gut says in aint -47

anonymous · Answer

So it would have to be -137 considering the values are negative right?

amistre64 · Answer

correct

anonymous · Answer

B