Packet #1 Flashcards
(31 cards)
Order of operations
Parentheses
Exponents
* / left to right
+ - left to right
What is an algebraic expression or variable expression?
Representation of unknown numbers. Usually use letters as placeholders for numbers.
Ex. 3x/xy/etc.
48/12+4/2+3
(48/12)+(4/2)+3
(4)+(2)+3
4+2+3=9
92-3(2(5-2))
92-3(2(5-2))
92-3(2(3))
92-3(6)
92-18=74
83-(4(12-7)/5
Over 5
(83) - 4(12-7)/5
(83) - 4(5)/5
(83)-20/5
83-4=79
Evaluate 9xy-4xz+3yz for x=7, y=3, z=2
9xy-4xz+3yz (9(7)(3))-(4(7)(2))+(3(3)(2)) (9(21))-(4(14))+(3(6)) 189-56+18 151
Greatest common factor
The highest number that divides exactly into 2 or more numbers.
Least common multiple
Smallest common multiple of two integers
Definition of “divides”
to separate (something) into two or more parts or pieces
3/6
3 divides 6 3 divides into 6 3 divides into 6 evenly 3 is a factor of 6 6 divided by 3 is even 3*2=6
why is 5 a factor of 15?
5*3=15
why does 20/60?
20*3=60
4 goes into 12 evenly because…
4*3=12
7 does not divide 12 evenly because…
7*1=1
7*2=14
what is a prime number?
a whole number that is divisible only by 1 and itself.
what is prime factorization?
(factor tree) breaks a composite number into the product of primes.
make factor tree for 12
12
/ \
4 * 3
/
2*2
rule of 2
if the number is even, it is divisible by 2
Rule of 3
a whole number is divisible by 3 if the sum of its digits is divisible by 3
rule of 5
a whole number is divisible by 5 if the units digit is divisible by 5
rule of 9
a whole number is divisible by 9 if the sum of the digits is divisible by 9
how to add integers with like signs
add their absolute values and take the common sign
how to add integers with unlike signs
subtract the smaller absolute value from the larger absolute value and take the sign of the larger.
(+)(+)
positive answer
