Solve for X in the Quadratic Equation: (x-5)²-5=10+2x

Question

Solve the following equation:

(x5)25=10+2x (x-5)^2-5=10+2x

Video Solution

Solution Steps

00:00 Find X
00:03 Use shortened multiplication formulas
00:15 Substitute appropriate values according to the given data and open the parentheses
00:35 Substitute in our equation
00:53 Arrange the equation so that one side equals 0
01:05 Collect like terms
01:23 Examine the coefficients
01:38 Use the root formula
01:55 Substitute appropriate values and solve
02:09 Calculate the square and multiplications
02:37 Factor 104 into factors 4 and 26
02:42 Break down the root into the root of each factor
02:46 Calculate root of 4
02:59 These are the two possible solutions (addition, subtraction)
03:31 And this is the solution to the problem

Step-by-Step Solution

To solve the given equation (x5)25=10+2x (x-5)^2 - 5 = 10 + 2x , we'll follow these steps:

  • Step 1: Expand and simplify the left side of the equation.
  • Step 2: Move all terms to form a standard quadratic equation.
  • Step 3: Use the quadratic formula to find the values of x x .

Now, let's work through each step:

Step 1: Expand the left side.
(x5)2=x210x+25 (x-5)^2 = x^2 - 10x + 25
The equation becomes:
x210x+255=10+2x x^2 - 10x + 25 - 5 = 10 + 2x

Step 2: Collect all terms on one side.
x210x+20=10+2x x^2 - 10x + 20 = 10 + 2x
Subtract 10+2x 10 + 2x from both sides to get:
x210x+20102x=0 x^2 - 10x + 20 - 10 - 2x = 0
This simplifies to:
x212x+10=0 x^2 - 12x + 10 = 0

Step 3: Apply the quadratic formula:
For ax2+bx+c=0 ax^2 + bx + c = 0 , the formula is x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} .
Here, a=1 a = 1 , b=12 b = -12 , c=10 c = 10 .
Calculate the discriminant:
b24ac=(12)24110=14440=104 b^2 - 4ac = (-12)^2 - 4 \cdot 1 \cdot 10 = 144 - 40 = 104
Now, solve for x x :
x=(12)±10421=12±1042 x = \frac{-(-12) \pm \sqrt{104}}{2 \cdot 1} = \frac{12 \pm \sqrt{104}}{2}

Therefore, the solutions to the equation are:
x1=6+1042 x_1 = 6 + \frac{\sqrt{104}}{2} , x2=61042 x_2 = 6 - \frac{\sqrt{104}}{2} .

This matches the correct choice, confirming that the solution is correct.

Answer

x1=6+1042,x2=61042 x_1=6+\frac{\sqrt{104}}{2},\\x_2=6-\frac{\sqrt{104}}{2}