Solving Quadratics by Completing the Square

What is the first step to solving THIS equation by completing the square?
a² + 10a + 21 = 0

• Set the equation equal to zero

• Divide 10 by 2 and add the result to both sides

• Add a² and 10a together

• Subtract the 21

When do you use the plus or minus symbol?
±

• After taking the square root of both sides

• After adding the square to both sides

• After taking half of b

• After setting the equation equal to zero

Complete the square for
x² + 12x + ____

• x² + 12x + 144

• x² + 12x + 36

• x² + 12x - 36

• x² + +12x - 144

Given the perfect square trinomial, identify the equivalent expression

• (x-18)²

• (x-9)²

• (x+81)²

• (x+9)²

Solve the equation by completing the square and then finding the roots. 
x²+ 6x - 4 = 36

• x = -7, 7

• x = 4, -10

• x = -4 +- √7

• x = 10, -4

Solve the following quadratics equation by completing the square... x^2 + 6x - 3 = 0

• x = −1 and 11

• x = 1 and −11

• x = −10 and 11

• x = −5 and 25

• x = -1 ± √6

• x = 1 ± √6

• x = 6 ± √1

• x = -6 ± √1

Which line contains a mathematical error when completing the square?

• Line 1

• Line 2

• Line 3

• Line 4

• There is no error

Which line contains a mathematical error when completing the square?

• Line 1

• Line 2

• Line 3

• Line 4

• Line 5