Math: Algebra Flashcards
7 cards from real ACT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Math: Algebra flashcards as text
What is the solution to the system of equations: x + y = 7 and x − y = 3?
Answer: x = 5, y = 2
Adding the equations gives 2x = 10, so x = 5; substituting back yields y = 2.
Which expression is equivalent to (2x + 3)²?
Answer: 4x² + 12x + 9
(2x + 3)² = (2x)² + 2(2x)(3) + 3² = 4x² + 12x + 9.
A line passes through the origin and the point (3, 9). What is the equation of the line?
Answer: y = 3x
The slope is 9/3 = 3, and since it passes through the origin (b = 0), the equation is y = 3x.
If 2ˣ = 32, what is the value of x?
Answer: 5
Since 2⁵ = 32, x = 5.
What is the product of the roots of the equation x² − 7x + 12 = 0?
Answer: 12
By Vieta's formulas, the product of the roots equals c/a = 12/1 = 12 (or factor: (x−3)(x−4) = 0, product = 3 × 4 = 12).
If 5 is a solution to the inequality ax > 10, which of the following could be a value of a?
Answer: 3
Substituting x = 5 gives 5a > 10, so a > 2; only a = 3 satisfies this condition.
What is the x-intercept of the function f(x) = 4x − 8?
Answer: 2
Set f(x) = 0: 4x − 8 = 0, so 4x = 8 and x = 2.