Solve: 8(x-√3)(√3+x)=2x² | Square Root and Quadratic Equation

Question

8(x3)(3+x)=2x2 8(x-\sqrt{3})(\sqrt{3}+x)=2x^2

Video Solution

Solution Steps

00:00 Solve
00:09 Use the shortened multiplication formulas
00:21 Use the commutative law
00:37 Use the shortened multiplication formulas and write the expression
00:45 Calculate the square of root 3
00:54 Divide by 2
01:04 Open parentheses properly
01:16 Arrange the equation so that 0 is on the right side
01:28 Divide by 3
01:38 Convert from p to square of 2
01:43 Again use the shortened multiplication formulas
01:49 To find the two possible solutions
02:01 And this is the solution to the question

Step-by-Step Solution

To solve the equation 8(x3)(3+x)=2x2 8(x-\sqrt{3})(\sqrt{3}+x) = 2x^2 , follow these steps:

  • Step 1: Simplify the left side using the difference of squares, which states (ab)(a+b)=a2b2(a-b)(a+b)=a^2-b^2. Here, we treat a=x a = x and b=3 b = \sqrt{3} . This gives us:

(x3)(3+x)=x2(3)2=x23(x-\sqrt{3})(\sqrt{3}+x) = x^2 - (\sqrt{3})^2 = x^2 - 3

  • Step 2: Multiply this by 8 as the equation is 8(x23) 8(x^2 - 3) .

This results in: 8(x23)=8x224 8(x^2 - 3) = 8x^2 - 24

  • Step 3: Substitute this into the equation to get: 8x224=2x2 8x^2 - 24 = 2x^2 .
  • Step 4: Rearrange terms and solve for x x by bringing all terms to one side:

8x22x224=0 8x^2 - 2x^2 - 24 = 0 which simplifies to 6x224=0 6x^2 - 24 = 0 .

  • Step 5: Factor out the common terms in the quadratic equation:

6(x24)=0 6(x^2 - 4) = 0

  • Step 6: Notice that using the difference of squares again, x24 x^2 - 4 factors to (x2)(x+2)(x-2)(x+2).

This yields: 6(x2)(x+2)=0 6(x-2)(x+2) = 0 .

  • Step 7: Solve (x2)(x+2)=0 (x - 2)(x + 2) = 0 and apply the zero product property:

This gives the solutions x2=0 x - 2 = 0 and x+2=0 x + 2 = 0 , thus x=2 x = 2 and x=2 x = -2 .

Therefore, the solution to the problem is ±2 \pm2 .

Answer

±2 \pm2