math
what is the order of operations?
pemdas: parentheses, exponents, (multiplication, division), (addition, subtraction)
a/b = c/d = ?
a*d = c*b
a*d = c*b = ?
a/b = c/d
a=b/c, what are b and c?
b=ac, c=b/a
what is an absolute value?
it's distance from 0
formula for percent of change
((NN - ON)/ON) * 100
what is the formula for a discount?
Discount=OriginalNumber*RateOfDiscount
what is the formula for simple interest?
interest=principal*rate*time
what is distrubutive property?
a(b+c) = ab+ac
what are irrational numbers?
numbers that cant be expressed as a fraction
what are the atributes of irrational numbers?
non-repeating non-terminating decimal. no exact place on number line
how do you approcimate rational numbers? sqrt
sqrt y: x < y < z (x and z = closest perfect square). outcome closest to y
equations for percent problems
base=part/percent, percent=part/base, part=base*percent
exponent rules
x^a * x^b = x^a+b,
x^a/x^b = x^a-b,
x^a/x^b = 1/x^b-a,
1/x^b = x^-b
(x^a)^b = x^ab,
(xy)^a = x^a*y^a,
(a/b)^c = a^c/b^c
zero and negative exponent rules
x^0=1,
(x^a/x^b)^-1 = (x^b/x^a)^1