Question

I need help answering this question please!

Answer 1

Answer:

  p(x) = x⁴ -7x³ +59x² -343x +490

Step-by-step explanation:

Each root is the zero of a binomial factor. That is, for root x = a, the polynomial has a factor (x -a). Complex roots come in conjugate pairs, so if there is a root 7i, there is also a root -7i.

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The given roots mean the polynomial can be written in factored form as ...

  p(x) = (x -2)(x -5)(x -7i)(x -(-7i))

We can combine multiply these factors together to simplify the polynomial.

  p(x) = (x² -7x +10)(x² +49)

  p(x) = x⁴ -7x³ +59x² -343x +490

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Additional comment

Combining the conjugate complex roots uses the special form for the factoring of the difference of squares.

  a² -b² = (a -b)(a +b)

  (x -7i)(x +7i) = x² -(7i)² = x² -49i² = x² +49 . . . . . where i = √(-1)