solving quadratic equations using quadratic formula

solving quadratic equations using quadratic formula

• 2.
  Solving Quadratic Equationsby using quadratic formula  In this lesson you will learn how to use the quadratic formula to solve any quadratic equation.
• 3.
  Quadratic formula  isused to solve any kind of quadratic equation. You can read this formula as: Where a  0 and b 2 – 4 a c ≥ 0. x equals the opposite of b, plus or minus the square root of b squared minus 4 a c, all divided by 2 a. 𝒙 = −𝒃 ± 𝒃 𝟐 − 𝟒𝒂𝒄 𝟐𝒂
• 4.
  Rule for Usingthe Quadratic Formula  The equation must be in standard form, It will be very helpful to list out a = , b = , and c = each time you use the formula to minimize your mistakes. 2 0x xba c  
• 5.
  : Set meto your standard  Write the following equations in standard form, then identify the values of a, b, c. 1.2x2 + 3x = 27 a= 2, b= 3, c= -272x2 + 3x -27=0 Activity 1
• 6.
  Solve by quadraticformula 1.2x2 + 3x = 27 1.2x2 + 3x – 27= 0 𝒙 = −𝒃 ± 𝒃 𝟐 − 𝟒𝒂𝒄 𝟐𝒂 𝒙 = −(𝟑) ± (𝟑) 𝟐−𝟒(𝟐)(−𝟐𝟕) 𝟐(𝟐) a= 2, b= 3, c= -27
• 7.
  2. 2x2 +7x=- 5  Solution: a= 2, b= 7 c= 5 2x2 +7x + 5 = 0 𝒙 = −𝒃 ± 𝒃 𝟐 − 𝟒𝒂𝒄 𝟐𝒂 𝒙 = −𝟕 ± (𝟕) 𝟐−𝟒(𝟐)(𝟓) 𝟐(𝟐)
• 8.
  3. x2 -2x= 8  Solution: a= 1, b= -2, c= -8 x2 – 2x - 8=0 𝒙 = −𝒃 ± 𝒃 𝟐 − 𝟒𝒂𝒄 𝟐𝒂 𝒙 = −(−𝟐) ± (−𝟐) 𝟐−𝟒(𝟏)(−𝟖) 𝟐(𝟏)
• 9.
  4. x2 -7x= 10  Solution: a=1, b= -7, c= -10 x2 - 7x -10 = 0 𝒙 = −(−𝟕) ± (−𝟕) 𝟐−𝟒(𝟏)(−𝟏𝟎) 𝟐(𝟏)
• 10.
  Exercises:  1. x2+ 10x + 9 = 0 2. x2 + 5x – 14 = 0 3. X2 + 7x = 4 Solve the following quadratic equations by using the quadratic formula