Advanced MathMediumPositive input where a quadratic equals a linear expression
Advanced Math practice question
For what positive value of x is x² − 2x − 3 equal to x + 1?
Answer: 4
x² − 2x − 3 = x + 1 → x² − 3x − 4 = 0 → (x − 4)(x + 1) = 0. The positive value is 4.
Common wrong answers
- If you answered 3
- 3 is a zero of x² − 2x − 3, not where it equals x + 1.
- If you answered 5
- 5 is x + 1 at the solution, not x.
- If you answered -1
- −1 is the other root, not positive.
More Advanced Math questions
- Medium
What are the solutions to x² − 5x + 6 = 0? - Medium
The graph of f(x) = (x − 3)² + 4 is a parabola. What are the coordinates of its vertex? - Medium
If x² − 2x − 8 = (x + 2)(x − a), what is the value of a? - Medium
If √(x + 5) = 4, what is the value of x? - Medium
If f(x) = x + 3 and g(x) = 2x, what is f(g(4))? - Medium
What are the solutions to x² + 6x + 8 = 0?
Not affiliated with the College Board. SAT is a trademark of the College Board.