Which of the following is the simplified form of -10 { x }^{ 2 } +20x+80 /x+2

A. 10x-40
b x+4
c. -10x+40
x-4

1 answer

To simplify the expression \(-10x^2 + 20x + 80\) divided by \(x + 2\), we can follow these steps:

  1. Factor the numerator: First, we'll take the numerator \(-10x^2 + 20x + 80\) and factor it.

    Factor out \(-10\): \[ -10(x^2 - 2x - 8) \]

    Now, we need to factor \(x^2 - 2x - 8\). We look for two numbers that multiply to \(-8\) and add to \(-2\). The numbers that satisfy this are \(2\) and \(-4\). Thus, we can factor it as: \[ x^2 - 2x - 8 = (x - 4)(x + 2) \]

    Therefore, the numerator can be rewritten as: \[ -10(x - 4)(x + 2) \]

  2. Rewrite the expression: The original expression can be rewritten now: \[ \frac{-10(x - 4)(x + 2)}{x + 2} \]

  3. Cancel out the common term: Since there's a common factor of \((x + 2)\) in both the numerator and the denominator, we can cancel it out (as long as \(x \neq -2\)): \[ -10(x - 4) \]

  4. Distribute: Finally, distribute \(-10\): \[ -10x + 40 \]

Thus, the simplified expression for \(-10x^2 + 20x + 80\) divided by \(x + 2\) is:

\[ -10x + 40 \]

From the given options, the answer is:

c. -10x + 40.