Solve the Quadratic: Expanding (x+3)^2 to Find x in 2x+5

Question

Solve the following equation:

(x+3)2=2x+5 (x+3)^2=2x+5

Video Solution

Solution Steps

00:00 Find X
00:03 Use the abbreviated multiplication formulas
00:13 Substitute appropriate values according to the data and open the parentheses
00:30 Substitute in our equation
00:50 Arrange the equation so that one side equals 0
00:58 Collect terms
01:09 Identify coefficients
01:24 Use the roots formula
01:48 Substitute appropriate values and solve
02:07 Calculate the square and products
02:14 The square root of 0 is always equal to 0
02:21 When the root equals 0, the equation will have only one solution
02:48 And this is the solution to the question

Step-by-Step Solution

To solve the equation (x+3)2=2x+5 (x+3)^2 = 2x + 5 , we proceed as follows:

  • Step 1: Expand the left side. Using the identity (a+b)2=a2+2ab+b2 (a+b)^2 = a^2 + 2ab + b^2 , we find:
    (x+3)2=x2+6x+9 (x+3)^2 = x^2 + 6x + 9 .

  • Step 2: Set the equation to zero by moving all terms to one side:
    x2+6x+9=2x+5 x^2 + 6x + 9 = 2x + 5
    Subtract 2x+5 2x + 5 from both sides:
    x2+6x+92x5=0 x^2 + 6x + 9 - 2x - 5 = 0
    This simplifies to:
    x2+4x+4=0 x^2 + 4x + 4 = 0 .

  • Step 3: Solve the quadratic equation x2+4x+4=0 x^2 + 4x + 4 = 0 . Notice this can be factored as:
    (x+2)2=0 (x+2)^2 = 0 .

  • Step 4: Solve for x x by setting the factor equal to zero:
    x+2=0 x+2 = 0 .
    Thus, x=2 x = -2 .

Therefore, the solution to the equation (x+3)2=2x+5 (x+3)^2 = 2x + 5 is x=2 x = -2 .

Answer

x=2 x=-2