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F.O.I.L stands for
What is first, outside, inside, last?
Factor: x2 - 3x - 4
What is: (x + 1) (x - 4)
(4 x 1= 4
-4 + 1= -3)
Factor: x2 + 16
What is: (x + 4) (x - 4)
(42 = 16)
Factor: 2x2 - x - 15
What is: (2x + 5) (x - 3)
(2 x 1 = 2
5 x 3 = 15
2(-3) + 5 = -1)
What is: same, opposite, always positive
The factor we pull out first
What is the Greatest Common Factor (GCF)
Find X: x2 + x + 6
What is: x= [-3, -2]
(-3 x -2 = 6
3 - 2 =1)
Find x: x2 + 25
( 5 x 5 = 25)
Factor: 2x2 - 9x - 81
What is: (2x + 9) (2x - 9)
Factor: (x3 + 8)
What is: (x + 2) (x2 - 2x + 4)
(cube root of 8 = 2 and of x cubed = x,
2(x) = 2x
22 = 4)
(x + 3) and (x - 2)
Factor: x2 - 2x - 8
What is: (x + 2) (x - 4)
(2 x 4 = 8
-4 + 2 = -2)
Find x: x2 - 64
What is: NONE !
(prime because of the '-')
Factor: 5x2 + 8x + 80
What is: Not Factorable
Factor: (x3 - 27)
What is: (x - 3)(x2 + 3x + 9)
To check...
FOIL the factors together !
Factor: x2 + 3x + 2
What is: (x + 1) (x + 2)
(1 x 2 = 2
1 + 2 = 3)
Factor: x2 + 81
What is: (x + 9) (x - 9)
(9 x 9 = 81)
Factor: 7x2 + 6x - 1
What is: (7x - 1)(x + 1)
Factor: (x3 + 125)
What is: (x + 5) (x2 - 5x + 25)
Quadratic function
What is ax2 + bx + c
Find x: x2 + 5x + 6
What is: x = [2, 3]
(2 x 3 = 6
2 + 3 = 5)
Find X: x2 + 169
What is: x = [-13, 13]
(13 x 13 = 169)
What is: (x - 8) (4x - 3)
Factor: (x3 + 64y)
What is: (x + 4y) (x2 - 4xy + 16y2)