Solving Quadratic Equations

Solving Quadratic Equations

by JadeAnthony Dosdos

​Objectives:

​At the end of the lesson, students should be able to:

​

​-solve quadratic equations by graphing.

​-solve quadratic equations algebraically.

​-solve real-life problems.

​Core Concepts:

​Steps on how to solve the roots/solutions:

​1. Find the factors of "c" by multiplication.

​2. Add the factors that the result is b.

​3. Plot the numbers.

​4. Put "x" in each quantities.

​5. Equate by zeroes in each quantities.

​Example:

​Find the roots or solutions in the given function.

Steps:​

1. Find the factors of "c" by multiplication.

​2. Add the factors that the result is b.

​3. Plot the numbers.

​4. Put "x" in each quantities.

​5. Equate by zeroes in each quantities.

​Solution:

​a = 1; b = -1; c = -6

​

​Factors of -6 are:

​3x-2 = -6

​-3x2 = -6

​1x-6 = -6

​6x-1 = -6

​3 + -2 = 1

​-3 + 2 = -1

​1 + -6 = -5

​6 + -1 = 5

​Continuation:

​-3 and 2

​( -3) ( 2)

​(x -3) (x +2)

​

​x -3 = 0

​ +3 = +3

​x = 3

​x +2 = 0

​ -2 = -2

​x = -2

Multiple Choice

Find the roots or solutions in this given function

$$x^2+5x+6\ =\ 0$$  

• x = 3

  x = 2

• x = 1

  x = 6

• x = -3

  x = -2

• x = -1

  x = -6

Multiple Choice

Find the roots or solutions in this given function

$$x^2-25=0$$  

• x = 5

  x = -5

• x = 20

  x = -5

• x = -5

  x = -5

• x = 5

  x = 5

Poll

Do you have any questions?

• Yes

• No