Which example correctly demonstrates polynomial subtraction? (1 point)

$(2x^{2}+6x+1)-(3x^{2}+3x+9)=-x^{2}+3x-8$
$(2x^{2}+6x+1)-(3x^{2}+3x+9)=-5x^{2}+3x-8$
$(2x^{2}+6x+1)-(3x^{2}+3x+9)=x^{2}+3x+8$
$(2x^{2}+6x+1)-(3x^{2}+3x+9)=5x^{2}+9x+10$

1 answer

To check which example correctly demonstrates polynomial subtraction, we need to perform the subtraction on the given polynomials:

\[ (2x^{2}+6x+1) - (3x^{2}+3x+9). \]

We can distribute the negative sign into the second polynomial:

\[ = 2x^2 + 6x + 1 - 3x^2 - 3x - 9. \]

Now, we can group the like terms together:

\[ = (2x^2 - 3x^2) + (6x - 3x) + (1 - 9). \]

Calculating each group:

  1. For the \(x^2\) terms: \[ 2x^2 - 3x^2 = -1x^2 \text{ or } -x^2. \]

  2. For the \(x\) terms: \[ 6x - 3x = 3x. \]

  3. For the constant terms: \[ 1 - 9 = -8. \]

Putting it all together, we have:

\[ -x^2 + 3x - 8. \]

Now we compare this result with the provided answer choices:

  1. \((-x^2 + 3x - 8)\)
  2. \((-5x^2 + 3x - 8)\)
  3. \( (x^2 + 3x + 8) \)
  4. \( (5x^2 + 9x + 10) \)

The first option matches our result exactly. Therefore, the correct example that demonstrates polynomial subtraction is:

\[ \boxed{(2x^{2}+6x+1)-(3x^{2}+3x+9)=-x^{2}+3x-8}. \]