# Pre-calc

posted by .

Use the given zero to find the remaining zeros of the function:

h(x)=x^4-15x^3+55x^2+155x-1476 Zero:5-4i

I multiplied [x-(5-4i)][x-(5+4i)] and got x^2-10x+9.

The example I have says to divide that by h and get a second quadratic equation that is also a factor of h. I have to use that equation to find the remaining zeros. How do I find the second equation?

• Pre-calc -

(x-(5-4i))(x-(5+4i))
= (x-5+4i)(x-5 - 4i)
= x^2 - 5x - 4ix - 5x + 25 + 20i + 4ix -20i - 16i^2
= x^2 - 10x + 41

now divide x^4-15x^3+55x^2+155x-1476 by x^2 - 10x + 41 to get

x^2 - 5x - 36

(Google " long algebraic division" if you don't know how to do that)

x^2 - 5x - 36 = 0
(x-9)(x+4) = 0
x = 9, or x = -4

## Similar Questions

1. ### Pre Calc

I am familiar with this type of problem but can't seem to get the right answer. Use the given zero to find the remaining zeros of each function f(x)=x^4-9x^3+7x^2-91x-348,zero 5-2i I normally would use synthetic division with the root …
2. ### Pre Calc (For Reiny)

Thanks so much your method worked perfectly! My solution was: the remaining zeros were 5+2i, 3, and -4 I have one question that's bugging me though, why is it that synthetic division did not work for me?
3. ### college algebra

use the given zero to find the remaining zeros of each function.g(x)=x^3+3x^2+25x+75;zero:-5i
4. ### college algebra

use the given zero to find the remaining zeros of the function h(x)=x^4-15x^3+60x^2+70x-816 zero: 5-3i
5. ### algebra

use the given zero to find the remaining zeros of the function h(x)=x^4-15x^3+60x^2+70x-816 zero: 5 show work

that should of said Zero: 5 - 3 i for the one that stated use the given zero to find the remaining zeros of the function h(x)=x^4-15x^3+60x^2+70x-816
7. ### pre-cal

use the given zero to find the remaining zeros of the function. h(x)=x^4-12x^3+36x^2+68x-525 zero:4-3i
8. ### calculus

use the given zeros to find the remaining zeros of the function h(x)=x^4-9x^3+12x^2+138x-1360 zero:3-5i enter the remaining zeros of f please show work
9. ### use the given zero

Use the given zero to find the remaining zeros of the function. f(x)=x^3-2x^2+9x-18;zero;3i Enter the remaining zeros of f =
10. ### Algebra

Use the given zero to find the remaining zeros of the function. f(x)=x^3-2x^2+9x-18;zero;3i Enter the remaining zeros of f =

More Similar Questions