GED Mathematical Reasoning TestAlgebraic Problem Solving with Expressions and EquationsMedium

A financial analyst is modeling the profit (P) of a new product based on its selling price (s) in dollars. The profit is given by the equation P = -2s² + 60s - 350. At what selling price(s) will the company break even (i.e., profit is zero)?

  1. A$20 and $40
  2. B$5 and $25
  3. C$10 and $35
  4. D$15 and $30
Show answer & explanation

Correct answer: C. $10 and $35

To find the break-even points, set the profit (P) to zero and solve the quadratic equation -2s² + 60s - 350 = 0. Divide by -2 to simplify, then factor or use the quadratic formula.

Why the other options are wrong

  • A. These values do not satisfy the equation when substituted.
  • B. These values do not satisfy the equation when substituted.
  • D. These values do not satisfy the equation when substituted.

Quadratic Equation Break-Even

The break-even point for a quadratic profit function is found by setting the profit (P) to zero and solving the resulting quadratic equation for the variable (e.g., selling price or quantity).

  • Represents the points where total revenue equals total cost.
  • Often yields two solutions for a quadratic equation.
  • Solutions can be found by factoring, completing the square, or using the quadratic formula.

Memory trick: Zero profit means solving the quadratic puzzle.

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