Quadratics and Form Conversions

Next step in converting to factored form: 0 = 0.5x + x - 12

0.5(x² + 2x —) -(—) - 12

What was the mistake made?

y = 0.5x² + x - 12

0 = 0.5(x² + 2x

They forgot to multiply the magic constant by two to account for x²’s coefficient

Factor x² - 2x - 80 (give steps)

Make a diamond table to figure what multiplies to -80 and adds up to -2, then use those two numbers to make factors.

1. y = x² -5x -4

2. y = x² -5x + 6.25 - 4

3. y = x² -5x + 2.25

4. y = (x - 2.5)² + 2.25

   Which step was the first error made in and why?

Step 2, you must add and subtract the magic constant (“cancel it out”)