Answer:
x = 1 or x = -5
Explanation:
We are given;
- The quadratic equation, x² + 4x - 13 = -8
We are required to solve the equation using the completing square method.
To do this, we use the following steps;
Step 1: We make sure the coefficient of x² is one
x² + 4x - 13 = -8
Step 2: Combine the like terms (take the constant term to the other side)
x² + 4x - 13 = -8
x² + 4x = -8 + 13
we get
x² + 4x = 5
Step 3: We add the square of half the coefficient of x on both sides of the equation
Coefficient of x = 4
Half of coefficient of x = 2
Square of half the coefficient of x = 2² (4)
We get;
x² + 4x + (2²) = 5 + (2²)
Step 4: Put x and 2 under one square and the solve the other side of the equation.
We get
(x + 2)² = 5 + 4
(x + 2)² = 9
Step 5: Get the square root on both sides of the equation;
(x + 2)² = 9
√(x + 2)² = ±√9
(x + 2)= ±3
Therefore;
x+2 = + 3 or x + 2 = -3
Thus, x = 1 or -5
The solution of the equation is x = 1 or x = -5