M8: Using Factors to Solve Quadratic Equations Flashcards
What solving method would you use to solve this equation?
4x^2 + 4x + 1
To solve easily, use the box method.
(x+6) (x-4)
x^2+2x-24
(2x+5) (x-3)
2x^2-x-15
(x-6) (x+1)
x^2-5x-6
(x^2+3) (x-4)
x^3-4x^2+3x-12
(x^2+11) (x+6)
x^3+6x^2+11x+66
(x^2+8) (x-5)
x^3-5x^2+8x-40
(x+3) (x+7)
x^2+10x+21
(4x+2) (x-2)
4x^2-6x-4
(3x+2) (2x+5)
6x^2+19x+10
(x^2-6) (x-4)
x^3-4x^2-6x+24
(x^2+9) (x-3)
x^3-3x^2+9x-27
(4x^2-4) (2x+1)
8x^3+4x^2-8x-4
(x-3) (x^2+2x+1)
x^3+x^2-5x-3
(x+5) (x^3+6x^2+18x)
x^4+11x^3+48x^2+90x
(x+4) (x^4+x^2+1)
x^2+x^3+x
Zero Product Property
set equation = to 0
Diamond Method
Diamond shape where you multiply a and c together and put them at the top point of the diamond then b at the bottom. To find the numbers on the side you must find 2 numbers that multiply to ac and also add to b.
What method should you use for the following equation : ax^2+bx+c
Diamond Method
x^2 + x - 6 = 6
Answer is x= -4 x= 3 Steps: x^2 + x - 12 = 0 (x + 4)(x - 3) = 0 x + 4 = 0 x-3 = 0 x = -4 x = 3
x^2 - 3x - 5 = 5
Answer is x = -2 x = 5 Steps: x^2 - 3x - 10 = 0 (x+2)(x-5)=0 x+2 = 0 x - 5 = 0 x= -2 x = 5
36x^2 + 84x + 40 = -9
Answer is x = -7/6 Steps: (Squiggle Line Method) 36x^2 + 84x + 49 = 0 ~~~~ ~~~~ 6x 7 42x (6x+7)^2 = 0 6x + 7 = 0 6x = -7 x = -7/6
4x^2 + 12x = -8
Answer is x = -1 , x = -2 Steps: 4x^2 + 12x + 8 = 0 4(x^2 + 3x + 2) = 0 4(x + 1) (x + 2) = 0 x + 1 = 0 x + 2 = 0 x = -1 x = -2 x = -1 , x = -2
x^2 + 8x + 16 = 33
Answer is x = -23 x = -9 Steps: 8/2 = 4^2 = 16 x^2 + 8x + 16 = 49 (x + 4)^2 = 49 x+16 = +/- √49 x+ 16 = +/- 7 -16= -16 x = -16 +/-7 x=-16-7 x=-16+7 x=-23 x=-9
Steps to finding what equation to use
- Get Equation to 0
- Identify A,B,C
- Check if A and C are perfect squares
( If so we can apply our shortcuts) - If A = 1 check if the reverse box method is possible
- If A is other than 1 try the diamond method
- Use completing the Square if there are negative numbers.
- Use the Quadratic formula when there are more fractions or positive numbers