Complete the Perfect Square: (□×x-□)² = 9x²-24x+16

Question

Fill in the blanks:

(?×x?)2=9x224x+16 (?\times x-?)^2=9x^2-24x+16

Video Solution

Solution Steps

00:00 Complete the missing part
00:03 We'll use the shortened multiplication formulas to find the brackets
00:11 We'll break down the first term into its square root
00:16 We'll do the same for the last term
00:23 We'll break down the middle term into factors 2, 3, and 4
00:34 We'll verify that the multiplication is correct
00:38 We'll substitute the numbers in their correct places
00:43 And this is the solution to the question

Step-by-Step Solution

To solve this problem, let's identify the steps needed to determine the missing values.

  • Step 1: Apply the perfect square formula.
    Write (a×xb)2=a2x22abx+b2(a \times x - b)^2 = a^2x^2 - 2abx + b^2.
  • Step 2: Compare with the given polynomial.
    Set the expression equal to the provided polynomial: 9x224x+169x^2 - 24x + 16.
  • Step 3: Match coefficients.
    From a2x2=9x2a^2x^2 = 9x^2, we get a2=9a^2 = 9.
    From 2abx=24x-2abx = -24x, we get 2ab=24-2ab = -24.
    From b2=16b^2 = 16, we get b2=16b^2 = 16.
  • Step 4: Solve for aa and bb.
    - Solve a2=9a^2 = 9, giving a=3a = 3 or a=3a = -3. Choose a=3a = 3 for simplicity.
    - Solve b2=16b^2 = 16, giving b=4b = 4 or b=4b = -4. Choose b=4b = 4 for simplicity.
    - Check 2ab=24-2ab = -24: 2(3)(4)=24-2(3)(4) = -24, which is correct.

Therefore, the missing values are 3,4 \boxed{3, 4} .

Thus, the solution to the problem is: 3,43, 4.

Answer

3, 4 3,\text{ }4