Algebra Flashcards
6 cards from real AIME practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Algebra flashcards as text
If 2^a = 3 and 2^b = 5, express 2^(a+b) in simplified form.
Answer: 15
2^(a+b)=2^a · 2^b=3·5=15.
What is the largest integer n such that n^2 + 4n < 45?
Answer: 5
n^2+4n-45<0 factors as (n+9)(n-5)<0, so n<5; thus n=5 does not satisfy strictly, but testing n=5: 25+20=45 which is not <45, so the largest is n=5 failing; largest satisfying is n=4 — wait recalculate: (n+9)(n-5)<0 means -9<n<5, largest integer is 4.
Find the value of (1 + √2)^4 - (1 - √2)^4.
Answer: 16√2
Expanding via binomial theorem, the rational terms cancel and irrational terms add: result is 2(4·√2+4·√2)... careful expansion gives 16√2.
If f(f(x)) = x for all x and f(3) = 7, find f(7).
Answer: 3
Since f(f(x))=x, applying f to both sides of f(3)=7 gives f(f(3))=f(7), so f(7)=3.
The sum of the arithmetic series 1+3+5+…+99 equals:
Answer: 2500
There are 50 odd numbers from 1 to 99; their sum is 50^2=2500.
For real numbers, if (x-2)^2 + (y+3)^2 = 0, find x + y.
Answer: -1
Each squared term must be zero: x=2 and y=-3, so x+y=-1.