Brandy is using the method of completing the square to solve the equation shown below.
x2 + 10x = 50
What term should Brandy add to both sides of the equation?
A. 5
Incorrect. This number is 1 2b, which is the number that should be squared in order to add to both sides of the equation.
B. 10
C. 25
Correct!
D. 100 
Shawn is completing the square to find c, so he can rewrite x2 - 14x + c as a squared binomial. His work is shown below.
In which step did Shawn make his first mistake?
A. Step 2
Incorrect. The value of b in the quadratic polynomial is -14.
B. Step 3
Incorrect. 1 2 b = 1 2 (-14) = -7, so this step is correct.
C. Step 4
Correct! (-7)2= 49, not -49.
D. Step 5 
Use the method of completing the square to find the value of c that makes x2 – 15x + c a perfect square trinomial.
A. 225
Incorrect. This number is the value of b2.
B. 56.25
Correct!
C. 15
Incorrect. This number is the value of b.
D. 7.5
Incorrect. This number is the value of 1 2b.
Yesenia used the model below to help her complete the square for the polynomial x2 + 6x.
What binomial squared can Yesenia write from her model?
A. (x+3)2
Correct!
B. (x−3)2
Incorrect. In the polynomial, the x-term is positive, so the sign of the binomial will be positive also.
C. (x−6)2
Incorrect. Look at the dimensions of the model that Yesenia is using.
D. (x+6)2
Incorrect. Look at the dimensions of the model that Yesenia is using.
Thach wants to determine the location of the vertex of the parabola represented by the equation y = x2 + 5x – 11. He decides to use the method of completing the square in order to convert the equation from polynomial form to vertex form. What will be the equation written in vertex form?
A. y = (x - 6.25)2 − 11
Incorrect. 6.25 is the number that will need to be added in order to complete the square, but Thach will also need to subtract 6.25 from the constant term in order to preserve the equality.
B. y = (x + 2.5)2 − 11
Incorrect. The binomial portion of this equation is correct, but you will also need to subtract 6.25 from the constant term in order to preserve the equality.
C. y = (x + 6.25)2 − 17.25
Incorrect. 6.25 is the number that will need to be added in order to complete the square, but is not the constant term in the binomial.
D. y = (x + 2.5)2 − 17.25
Correct!