SAT Math · Nonlinear equations in one variable · medium
What is the solution to √(2x+3) = x, after rejecting any extraneous candidate?
What is the solution to , after rejecting any extraneous candidate?
Answer and explanation
Answer: B: 3
Square both sides of to get . Rearrange: , which factors as , so or . Squaring can introduce extraneous solutions, so check both. For : , which is true. For : , but the right side is , so it fails. The only solution is 3, choice B. Choice A () is the extraneous root, choice C includes both without checking, and choice D (9) is the value under the radical, not .
More Nonlinear equations in one variable questions
- Question 10 · mediumFor what positive value of k does the equation x² - kx + 9 = 0 have exactly one real solution?
- Question 11 · hardThe equation x² - 7x + c = 0 has two real solutions that differ by 3. What is the value of c?
- Question 12 · mediumWhat value of x satisfies 8^x+1 = 32^x-2?
- Question 26 · mediumIf |2x - 5| = 11 and x is negative, what is the value of x?
- Question 34 · mediumWhat is the sum of all values of x that satisfy 2^x²-5x = 2^-6?
- Question 63 · hardWhat is the sum of all real solutions to x^4 - 13x² + 36 = 0?
Learn the method behind questions like this one
The SAT Math course teaches each tested skill through lessons, step-by-step solutions to sample problems, the complete study guide and full-length practice tests.