Algebraic Equations and Functions Flashcards
7 cards from real GRE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Algebraic Equations and Functions flashcards as text
Solve the system: x + y = 10 and x - y = 4. What is x?
Answer: 7
Adding the equations gives 2x = 14, so x = 7.
Factor completely: x² - 9.
Answer: (x - 3)(x + 3)
This is a difference of squares: x² - 9 = (x - 3)(x + 3).
If f(x) = x² - 4x + 4, what are the roots?
Answer: x = 2 (double)
x² - 4x + 4 = (x - 2)², so x = 2 is a repeated root.
Simplify: (2x³)(3x²).
Answer: 6x⁵
Multiply coefficients (2·3 = 6) and add exponents (3 + 2 = 5) to get 6x⁵.
If 3^x = 81, what is x?
Answer: 4
Since 81 = 3⁴, x = 4.
What is the y-intercept of f(x) = -2x + 7?
Answer: 7
The y-intercept occurs at x = 0, giving f(0) = 7.
Solve for x: (x/3) + 2 = 6.
Answer: 12
Subtract 2 to get x/3 = 4, then multiply by 3 to get x = 12.