factoring formulas (wong).

sum/differences of squares

a² - b² = (a + b)(a - b). when using this formula, square root the 'a' and 'b' values. example: 9c² - 4d² = (3c + 2d)(3c - 2d)

sum/differences of two cubes

difference of two cubes: a³ - b³ = (a - b)(a² + ab + b²). when using this formula, take out the monomial, then square root the value. example: 40c³ - 5d³ = 5(8c³ - d³) = 8c³ = (2c)³ = 5(2c - d)(4c² - 2cd + d²). sum of two cubes: a³ + b³ = (a + b)(a² - ab + b²).

complex numbers

i= √-1. i² = -1. i³ = -i. i⁴ = 1. i⁵ = i. example: divide a number by 4, if there is no remainder than it is 1. if there is a remainder, multiply i⁴ and i(remainder value).

discriminant

the discriminant is everything inside the square root. if a discriminant is greater than zero, there are two solutions. if a discriminant is equal to zero, there is one solution. if a discriminant is less than zero, there are no real solutions and there are two imaginary solutions.

quadratic formula

x = -b ± √(b² - 4ac)/2a. plug in a problem, and it will give you the answer.