Michelle A.
Algebra 2
Chapter 6: Exploring Quadratic Functions and Inequalities (Glencoe algebra 2 edition)
Completing the Square
In math class on Tuesday Mrs. Bag Lady was teaching the students a lesson on completing the square. He gave them this problem to do x2 + 10x + 5 = 0 and told them to solve it by the new method they have learned.
Here are the steps in solving the problem by completing the square
Step 1: Take and subtract 5 from each side of the equation so that u can get rid of the 5 and have it in place of the 0.
| x2 + 10x + 5 = 0 |
| - 5 -5 |
| x2 + 10x = -5 |
Step 2: Take half of the number in front of the term X and square it, then add it to both sides of the equation.
| x2 + 10x = -5 half of 10 is 5, squared 25 |
| x2 + 10x +25 = -5 +25 |
| x2 + 10x +25 = 20 |
Step 3: Factor out the left side of the equation if possible.
| x2 + 10x + 25 =20 |
| (x + 5)(x +5) = 20 |
| (x + 5)2 = 20 |
Step 4: Take the square root of both sides of the equation.
| (x + 5)2 = 20 |
| (x + 5) =2 square root of 5 |
| (x +5) = + 2 square root 5 |
Step 5: Set up a "T" Chart to find the final answers. This will allow you complete the square.
| x + 5 = 2 square root 5 (subtracting 5 from both sides) | x + 5 = - 2 square root 5 (subtracting 5 from both sides) |
| x = -.528 | x = -9.472 |
| The final answers are -.528 and -9.472 | |
CONGRATULATIONS YOU HAVE JUST COMPLETED THE SQUARE OF A PROBLEM!!!!!
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