Unit 1 Math
Prime number: a number that is divisible by only 1 and itself.
Composite number: a number that has a factor other than 1 or itself.
1 is neither prime nor composite.
check divisibility rules
if not obvious yet, find the square root
find all the prime numbers less than the square root
if none of the primes are a factor, then the original number is prime
includes each factor the greatest number of times it occurs
ex. prime factorization of 20 = 2x2x5 and 30 = 2x3x5
LCM of 20 and 30 = 2x2x3x5
LCM = 60
find all similar factors and put them together
ex. prime factorization of 2940 = 2x2x3x5x7x7 and 3150 = 2x3x3x5x5x7
GCF of 2940 and 3150 = 2x3x5x7
GCF = 210
first term is a perfect square
second term is a perfect square
they are separated by a minus sign
rule out any common factor
multiply coefficient of first term by coefficient of last term
find the factor pair of that number that adds/subtracts to equal coefficient of second term
split the second term into 2 terms
then factor and check
Prime number: a number that is divisible by only 1 and itself.
Composite number: a number that has a factor other than 1 or itself.
1 is neither prime nor composite.
check divisibility rules
if not obvious yet, find the square root
find all the prime numbers less than the square root
if none of the primes are a factor, then the original number is prime
includes each factor the greatest number of times it occurs
ex. prime factorization of 20 = 2x2x5 and 30 = 2x3x5
LCM of 20 and 30 = 2x2x3x5
LCM = 60
find all similar factors and put them together
ex. prime factorization of 2940 = 2x2x3x5x7x7 and 3150 = 2x3x3x5x5x7
GCF of 2940 and 3150 = 2x3x5x7
GCF = 210
first term is a perfect square
second term is a perfect square
they are separated by a minus sign
rule out any common factor
multiply coefficient of first term by coefficient of last term
find the factor pair of that number that adds/subtracts to equal coefficient of second term
split the second term into 2 terms
then factor and check