Q. Rewrite the equation by completing the square.x2+3x−28=0(x+□)2=□
Write Original Equation: Write down the original equation.The original equation is x2+3x−28=0.
Move Constant Term: Move the constant term to the other side of the equation.To complete the square, we need to have the x-terms on one side and the constant on the other side. So we add 28 to both sides of the equation:x2+3x=28
Find Completion Number: Find the number to complete the square.To complete the square, we need to add (2b)2 to both sides of the equation, where b is the coefficient of x. In this case, b=3, so (23)2=(1.5)2=2.25.
Add Completion Number: Add (2b)2 to both sides of the equation.We add 2.25 to both sides of the equation to complete the square:x2+3x+2.25=28+2.25
Write Left Side: Write the left side of the equation as a square of a binomial.The left side of the equation is now a perfect square trinomial, which can be written as the square of a binomial:(x+1.5)2=30.25
Simplify Right Side: Simplify the right side of the equation.We simplify the right side of the equation to get the final completed square form:(x+1.5)2=30.25
More problems from Solve a quadratic equation by completing the square