Algebra Flashcards
6 cards from real AMC12 practice questions. Tap to flip, then mark Knew It or Still Learning โ missed cards come back until you master them.
Read the first 6 Algebra flashcards as text
If 2^x = 3, what is the value of 4^x?
Answer: 9
4^x = (2^2)^x = (2^x)^2 = 3^2 = 9.
The roots of x^2 - 5x + 6 = 0 are r and s. What is r^2 + s^2?
Answer: 13
By Vieta's, r+s=5 and rs=6, so r^2+s^2=(r+s)^2-2rs=25-12=13.
If log2(x) + log2(x-2) = 3, find x.
Answer: 4
x(x-2)=8 gives x^2-2x-8=0, so (x-4)(x+2)=0 and x=4.
For what positive k does 3x^2 + kx + 12 = 0 have exactly one real solution?
Answer: 12
The discriminant k^2-144=0 gives k=12.
If f(x) = 2x+1 and g(x) = x^2, what is f(g(3))?
Answer: 19
g(3)=9 and f(9)=2(9)+1=19.
Solve |2x-3|=7. What is the sum of all solutions?
Answer: 3
2x-3=7 gives x=5 and 2x-3=-7 gives x=-2; sum=3.