Quadratic Formula

Determine the values of
a, b, and c for
the quadratic equation: 
4x² – 8x = 3

• a = 4, b = -8, c = 3
• a = 4, b =-8, c =-3
• a = 4, b = 8, c = 3
• a = 4, b = 8, c = -3

Solve using the quadratic formula.
2x² - 9x - 35 = 0

• x = 7/2, x = -6
• x = -5/2, x =5
• x = -3/7, x =6
• x = -5/2, x = 7

What should you do first in solving this equation?
x² + 6x - 13 = 3

• Get factored form
• Write down: a=1, b=6, c=-13
• Make it equal 0 by subtracting 3 on each side
• Type it all in a calculator.

Identify the values of A, B, and C

5x² + x - 18 = - 9x + 3x²

• A=2, B=10, C=-18

• A=5, B=1, C=-18

• A=8, B=-8, C=-18

• A=2, B=9, C=-18

 $x^2-5x\ -14\ =\ 0$  

Determine the x-intercepts by completing the quadratic formula. 
 $x=\ \frac{5\ \pm\sqrt{\left(-5\right)^2-4\left(1\right)\left(-14\right)}}{2\left(1\right)}$  

•  $x=\frac{5\pm\sqrt{-31}}{2}$  

•  $x\ =\ -7,\ x\ =\ 2$  

•  $x\ =\ 7,\ x\ =\ -2$  

•  $no\ solution$  

 $2x^2-14x+23=0$  
Simplify the final steps of the formula. 
 $x=\frac{14\ \pm\sqrt{12}}{4}$  

•  $x=\frac{14\pm6}{4}$  

•  $x=\frac{14\pm\sqrt{3}}{4}$  

•  $x\ =\ \frac{7\pm\sqrt{3}}{2}$  

•  $x=\frac{14\pm2}{4}$  

 $For\ 2x^2\ -\ 4x\ +\ 3\ =\ 0,\ which\ is\ correct?$  

•  $\frac{4\ \pm\sqrt{-16\ -4\left(2\right)\left(3\right)}}{2\left(2\right)}$  

•  $\frac{-4\ \pm\sqrt{16\ -4\left(2\right)\left(3\right)}}{2\left(2\right)}$  

•  $\frac{4\pm\sqrt{16-4\left(2\right)\left(3\right)}}{4}$  

•  $\frac{4\pm\sqrt{40}}{4}$  

if a = 2, b = 4 and c = 10,  what are the errors in

 $\frac{4\ \pm\sqrt{16\ -\ 4\left(2\right)\left(-10\right)}}{2}$  

• The 4 outside the radical should be negative.

• The denominator should be 4, not 2.

• 10 should be positive and not negative.
  
  

• All of the above

Solve

 $2x^2+4x\ +10=0$  

Simplify answers

•  $-4\ \pm8i$  

•  $-1\pm2i$  

•  $\frac{-4\ \pm8i}{4}$  

•  $\pm8i$  

Solve the equation for all real solutions in simplest form.
 $8x^2+11x+7=6x^2$  

•  $-2\pm\sqrt{65}$  

•  $\frac{-2\pm\sqrt{65}}{4}$  

•  $\frac{-11\pm\sqrt{65}}{4}$  

•  $\frac{-11\pm\sqrt{77}}{4}$  

•  $\frac{-11\pm\sqrt{177}}{4}$