Expand [4(2-x)]²: Square Brackets and Binomial Expression

Question

[4(2x)]2= \lbrack4(2-x)\rbrack^2=

Video Solution

Solution Steps

00:00 Simply
00:03 Open brackets properly, multiply by each factor
00:18 Use the shortened multiplication formulas to open the brackets
00:26 In this case, 8 is A
00:30 4X is B
00:38 Calculate 8 squared
00:42 Solve the multiplications
00:49 Raise each factor in the multiplication to the second power
00:57 Use the commutative law and arrange the exercise
01:03 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Simplify inside the bracket.
  • Step 2: Apply the square of a binomial formula.
  • Step 3: Expand and simplify the expression.

Now, let's work through each step:

Step 1: Simplify inside the bracket:
The expression inside the bracket is 4(2x)4(2-x). Multiplying through by 4, we have:
=4×(2x)=84x= 4 \times (2-x) = 8 - 4x.

Step 2: Apply the square of a binomial formula:
We want to compute (84x)2(8 - 4x)^2. According to the binomial formula:
(ab)2=a22ab+b2(a-b)^2 = a^2 - 2ab + b^2.

Let a=8a = 8 and b=4xb = 4x. Substituting these into the formula gives us:
(84x)2=822(8)(4x)+(4x)2(8 - 4x)^2 = 8^2 - 2(8)(4x) + (4x)^2.

Step 3: Expand and simplify the expression:
=6464x+16x2= 64 - 64x + 16x^2.

The correctly expanded expression is:
Therefore, the solution to the problem is 16x264x+64\mathbf{16x^2 - 64x + 64}.

Answer

16x264x+64 16x^2-64x+64