Question

PLEASE HELP WILL GIVE MEDAL!! Find all the zeros of each equation.

picture down bellow! ( i only need help on question #3)

Answer 1

A and D are out, because if \(i\) is a zero, then so is \(-i\)

Answer 2

now you can check if \(3\) is a zero or not, by substitution

Answer 3

actually none of those answers are right, i suspect you made a typo

Answer 4

i mean for the first problem you wrote
none of those answers are correct

Answer 5

\[x^5 – 3x^4 – 15x^3 – 45x^2 – 16x + 48 = 0\] right?

Answer 6

oh i see, it was a typo
it should have been \(+45x^2\) not \(-45x^2\)

Answer 7

ohh i thought u meant in the answer choices

Answer 8

in that case the zeros are \(3,-4,4,i,-i\)

Answer 9

thank u so much! do u know the other ones?

Answer 10

yes

Answer 11

\[x^3-x^2+5x-5=0\] first thing to check is that \(1\) is a solution, because it is, and it is easy to check
\[1-1+5-5=0\]

Answer 12

then you know you can factor it as
\[(x-1)(something)\] and you can find the something by division (synthetic division is easiest)

Answer 13

when you factor it, you should get
\[(x-1)(x^2+5)\] and so if \(x^2+5=0\) then \(x=\pm\sqrt{5}i\)

Answer 14

okk..then what do i do?

Answer 15

then you are done with that oneo

Answer 16

solutions are \(1,\sqrt5 i, -\sqrt5 i\)

Answer 17

is that one of the options or did u put it in a different order? haha im trying to figure it out lol

Answer 18

i don't know i didn't look at the options

Answer 19

oh i see, it is option A
no one writes \(i\sqrt5\) though, looks weird

Answer 20

ohhh ok yeah haha! can u help me with the last one?