Written as a simplified polynomial in standard form, what is the result when (2x - 7) ^ 2 is subtracted from 4?

1 answer

To solve the problem, we need to follow these steps:

  1. Expand the expression \((2x - 7)^2\).
  2. Subtract this expanded polynomial from 4.
  3. Simplify the result to get it into standard form.

Step 1: Expand \((2x - 7)^2\)

Using the formula \((a - b)^2 = a^2 - 2ab + b^2\), we get:

\[ (2x - 7)^2 = (2x)^2 - 2 \cdot (2x) \cdot 7 + 7^2 \]

Calculating each part:

  • \((2x)^2 = 4x^2\)
  • \(-2 \cdot (2x) \cdot 7 = -28x\)
  • \(7^2 = 49\)

Putting it all together:

\[ (2x - 7)^2 = 4x^2 - 28x + 49 \]

Step 2: Subtract this from 4

Now we subtract \(4x^2 - 28x + 49\) from 4:

\[ 4 - (4x^2 - 28x + 49) \]

This can be rewritten as:

\[ 4 - 4x^2 + 28x - 49 \]

Step 3: Simplify the expression

Now we combine like terms:

\[ 4 - 49 = -45 \]

Thus, we have:

\[ -4x^2 + 28x - 45 \]

Finally, writing it in standard form gives:

\[ -4x^2 + 28x - 45 \]

So the result when \((2x - 7)^2\) is subtracted from 4 is:

\[ \boxed{-4x^2 + 28x - 45} \]