GRE_math Flashcards
(25 cards)
odd*odd=
odd
odd +/- odd =
even
even*even =
even
even +/- even =
even
oddodd
odd
eveneven
even
evenodd
even
(a+b)(a-b) = ?
a2-b2
What’s x?

These are similar triangles, so use a proportion to solve
x/12 = 20/15


All inscribed triangles with a side that is a diameter of the circle are…
Right Triangles!
Area of a parallelogram
A = B*H
-(-4 < -x)
Reverse the inequality sign
4 > x
if m > n, q( m> n) =…
qm > qn if q is positive
qm < qn if q is negative
qm = qn if q is zero
Shortcut for figuring out which fraction is bigger:
7/16 vs. 3/7
Don’t find the common denominator, just find the numerator

Shortcut
What’s 7/12 + 3/5?
Combine into one fraction. Cross multiply for numerator and multiply denominators.
((7x5) + (3x12))/12*5

Shortcut
What’s 7/12 - 3/5?

Shortcut
What’s 4/250 in decimal form?
Multiply by 4/4 to get 16/1000 = 0.016
Name 8 right triangles

What is c if:
200 = (a+b+c)/2
80 = (a+b)/3



What is the sum of the integers from 13 to 75, inclusive?
If it’s between x-y, use the formula y*(y+1)/2 - (x-1)*x/2

How would you solve |x+4| > 6 ?
This is saying that whatever is inside of the absolute value symbol has to be more than 6 away from 0
So split this into: |x+4| > 6 AND |x+4| < -6 ?
What’s the formula for compound interest?
P = principal amount (the initial amount you borrow or deposit)
r = annual rate of interest (as a decimal)
t = number of years the amount is deposited or borrowed for.
A = amount of money accumulated after n years, including interest.
n = number of times the interest is compounded per year
