Change Vertex Form to Standard Form

Your teacher gives you an equation in vertex form and wants you to convert it to standard form. Which one of the following describes the steps in the correct order?

• Distribute the "a" value.

  Square the expression in parentheses.

  Combine like terms.

• Sketch the graph on the coordinate plane.

  Identify 2 ordered pairs.

  Use STAT-EDIT and STAT>CALC-Option 4 (LinReg)

• Square the expression in parentheses.

  Combine Like Terms.

  Distribute the "a" value.

• Square the expression in parentheses.

  Distribute the "a" value.

  Combine like terms.

Convert the equation from vertex form (shown) to standard form:

• y = 9x² - 15x + 21

• y = -3x² - 75x - 4

• y = 9x² + 90x + 221

• y = -3x² - 30x - 79

Convert the equation into standard form:

• y = -5x² - 20x - 30

• y = -5x² - 4x - 10

• y = 25x² + 100x + 90

• y = 25x² - 10x - 30

Which answer choice(s) below correctly show(s) an equation in vertex form and in its standard form? (There may be more than 1.)

• y = -3(x + 2)² + 3

  y = -3x² - 12x - 15

• y = 2(x + 5)² + 1

  y = 2x² + 20x + 51

• y = 0.5(x - 3)² - 6

  y = 0.5x² - 3x - 1.5

• A
• B
• C
• D

• A
• B
• C
• D

• y = -5x² - 20x - 30

• y = -5x² - 4x - 10

• y = 25x² + 100x + 90

• y = 25x² - 10x - 30

• y = 9x² - 15x + 21

• y = -3x² - 75x - 4

• y = 9x² + 90x + 221

• y = -3x² - 30x - 79