1997 CEMC Pascal Problems/Problem 6

Problem

If $x = -2$, the value of $(x)(x^2)(\frac{1}{x})$ is

$\text{ (A) }\ 4 \qquad\text{ (B) }\ -8\frac{1}{2} \qquad\text{ (C) }\ -4 \qquad\text{ (D) }\ -8 \qquad\text{ (E) }\ 16$

Solution 1

We can simply plug in $x = -2$ into the expression, and see what we get:

$(x)(x^2)(\frac{1}{x}) = (-2)((-2)^2)(\frac{1}{-2})$

$=-2 \times 4 \times \frac{1}{-2} = -8 \times \frac{1}{-2} = \boxed {\textbf {(A) } 4}$

~anabel.disher

Solution 2

We can simplify this, and then plug in $x = -2$ into the expression:

$(x)(x^2)(\frac{1}{x}) = x \times x^2 \times \frac{1}{x}$

$=x^3 \times \frac{1}{x} = x^2 = (-2)^2 = \boxed {\textbf {(A) } 4}$

~anabel.disher