SAT Math · Nonlinear equations in one variable · medium
What value of x satisfies 5^x+3 = 25^x-2?
What value of satisfies ?
Answer and explanation
Answer: D: 7
Rewrite both sides with base 5. Since , the right side is . Equate exponents: . Subtract and add 4: , choice D. Check: on the left and on the right. Choice A (1) gives versus . Choice B () gives versus . Choice C (5) gives versus . A common error is writing the right exponent as , forgetting to distribute the 2 over both terms.
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 33 · mediumWhat is the solution to √(2x+3) = x, after rejecting any extraneous candidate?
- Question 34 · mediumWhat is the sum of all values of x that satisfy 2^x²-5x = 2^-6?
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.