Solve by Completing the Square Practice

What do you do to the b value to correctly complete the square?

• square it
• divide it by 2 and square the result
• divide it by 2 and take the square root of the result
• divide it by 2 only

Which line contains a mathematical error when completing the square?

• Line 1

• Line 2

• Line 3

• Line 4

• There is no error

• Subtract 21 from each side of the equation.

• Add 21 to each side of the equation.

• Divide -10 by 2, square it, and then add 25 to each side.

• Divide -10 by 2, square it, and then subtract 25 from each side.

Which line contains a mathematical error when completing the square?

• Line 1

• Line 2

• Line 3

• Line 4

• Line 5

Solve by completing the square:
k² − 12k + 23 = 0

• {6 + √13, 6 - √13}
• {-6 + √13, -6 - √13}
• {6 + √59, 6 - √59}
• {-6 + √59, -6 - √59}

The work above shows the first two steps to solve by completing the square. Which description correctly describes the error that was made?

• They needed to add -1 to both sides.

• They needed to factor out the 2 so a = 1.

• They needed to take the square root of 4 first.

• They needed to add 4 to both sides.

• 6

• 36

• -6

• -12