Question

Please can someone answer this.

Answer 1

• x = -4, x = 0, x = 1

Explanation:

x is a factor of all terms, so x=0 is a zero. (Eliminates choices 1 and 5.)

The sum of coefficients is 0, so x=1 is a zero. (Eliminates choices 3 and 4.)

Reversing the sign of the odd-degree terms gives signs of -++, so there is one sign change, hence one negative real root (by Descartes' rule of signs). This confirms choice 2 as the answer.

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Of course, your graphing calculator can answer this almost as quickly.