SAT Algebra & Functions 3 — Questions and Answers
Question 1: A function is defined by g(x) = 5x + 2. For what value of x does g(x) = 27?
- 5 (Correct answer)
- 7
- 25
- 29
Correct answer: 5
Set 5x + 2 = 27, so 5x = 25 and x = 5.
Question 2: What is the y-intercept of the line 4x - 2y = 8?
- -4 (Correct answer)
- 4
- 2
- -2
Correct answer: -4
Set x = 0: -2y = 8, so y = -4.
Question 3: If a^2 = 49 and a < 0, what is a?
- -7 (Correct answer)
- 7
- -49
- 24.5
Correct answer: -7
The square roots of 49 are 7 and -7, and the negative one is -7.
Question 4: Solve the system: x + y = 10 and x - y = 4. What is x?
- 7 (Correct answer)
- 3
- 6
- 4
Correct answer: 7
Adding the equations gives 2x = 14, so x = 7.
Question 5: What is the value of the expression 3x^2 - 2x when x = 3?
- 21 (Correct answer)
- 15
- 27
- 3
Correct answer: 21
3(9) - 2(3) = 27 - 6 = 21.
Question 6: If the vertex of a parabola y = x^2 - 6x + 5 is at x = h, what is h?
- 3 (Correct answer)
- -3
- 6
- 5
Correct answer: 3
The vertex x-coordinate is -b/(2a) = 6/2 = 3.
Question 7: Simplify (6x^2 + 4x) / 2x, assuming x is not zero.
- 3x + 2 (Correct answer)
- 3x^2 + 2
- 3x + 4
- 6x + 2
Correct answer: 3x + 2
Dividing each term by 2x gives 3x + 2.
SAT Algebra & Functions 3
A function is defined by g(x) = 5x + 2.
For what value of x does g(x) = 27?