SAT Math Multiple Choice Question 937: Answer and Explanation
5. In the quadratic equation above, j and k are constants. What are the solutions for x?
Correct Answer: A
Category: Passport to Advanced Math / Quadratics
Strategic Advice: When an equation involves fractions, it is usually best to clear the fractions first to avoid messy calculations later. Also, when the answer choices involve square roots, you'll need to use the quadratic formula,.
Getting to the Answer: Multiply both sides of the equation by 3 to eliminate the fraction on the right side, and then subtract j from both sides to yield 3x2 + 6kx - j = 0. This means a = 3, b = 6k, and c = - j. Substitute these values into the quadratic formula, and then simplify as shown below:
Choice (A) is correct.