Simplify (x/3-4)² + x(√8x/3+2)(√8x/3-2): Complete Solution

Question

(x34)2+x(8x3+2)(8x32)=? (\frac{x}{3}-4)^2+x(\frac{\sqrt{8x}}{3}+2)(\frac{\sqrt{8x}}{3}-2)=\text{?}

Video Solution

Solution Steps

00:00 Simply
00:07 We'll use the shortened multiplication formulas to open the parentheses
00:20 Shortened multiplication formulas for this case
00:24 We'll use this formula in our exercise
00:39 Square both numerator and denominator
00:44 Calculate 4 squared
00:51 Square both numerator and denominator
01:05 Open parentheses properly, multiply by each factor
01:14 Collect terms
01:31 Simplify what we can
01:36 And this is the solution to the question

Step-by-Step Solution

Let's solve this problem by simplifying each component separately:

First, simplify (x34)2(\frac{x}{3} - 4)^2 using the square of a difference formula:

(x34)2=(x3)22×x3×4+42 (\frac{x}{3} - 4)^2 = \left(\frac{x}{3}\right)^2 - 2 \times \frac{x}{3} \times 4 + 4^2 This becomes:

=x298x3+16 = \frac{x^2}{9} - \frac{8x}{3} + 16

Next, simplify x(8x3+2)(8x32)x(\frac{\sqrt{8x}}{3} + 2)(\frac{\sqrt{8x}}{3} - 2) using the difference of squares formula:

(8x3+2)(8x32)=(8x3)222 (\frac{\sqrt{8x}}{3} + 2)(\frac{\sqrt{8x}}{3} - 2) = \left(\frac{\sqrt{8x}}{3}\right)^2 - 2^2 Simplify further:

=8x94 = \frac{8x}{9} - 4

Including the factor of xx, we have:

x(8x94)=8x294x x \left(\frac{8x}{9} - 4\right) = \frac{8x^2}{9} - 4x

Combine the results from both parts:

(x298x3+16)+(8x294x) \left(\frac{x^2}{9} - \frac{8x}{3} + 16\right) + \left(\frac{8x^2}{9} - 4x\right)

Simplify by combining like terms:

=x29+8x298x34x+16=x2(8x3+4x)+16=x2(8x+12x3)+16=x220x3+16 = \frac{x^2}{9} + \frac{8x^2}{9} - \frac{8x}{3} - 4x + 16 = x^2 - \left(\frac{8x}{3} + 4x\right) + 16 = x^2 - \left(\frac{8x + 12x}{3}\right) + 16 = x^2 - \frac{20x}{3} + 16

Therefore, after simplifying, the expression becomes x220x3+16\boldsymbol{x^2 - \frac{20x}{3} + 16}.

The final solution is: x220x3+16 x^2 - \frac{20x}{3} + 16 .

Answer

x2623x+16 x^2-6\frac{2}{3}x+16