Example

Finding Two Consecutive Integers Whose Product Is 132

Apply the seven-step problem-solving strategy to find two consecutive integers when their product is known, producing a quadratic equation rather than the linear equation that arises from sum problems.

Problem: The product of two consecutive integers is 132. Find the integers.

  1. Read the problem.
  2. Identify what to find: two consecutive integers.
  3. Name the unknowns: Let nn = the first integer. Then n+1n + 1 = the next consecutive integer.
  4. Translate into an equation: "The first integer times the next integer is 132" becomes:

n(n+1)=132n(n + 1) = 132

  1. Solve the equation. Distribute on the left side:

n2+n=132n^2 + n = 132

Subtract 132 from both sides to obtain standard form:

n2+n132=0n^2 + n - 132 = 0

Factor the trinomial by finding two numbers whose product is 132-132 and whose sum is 11. The pair 1212 and 11-11 works (12(11)=13212 \cdot (-11) = -132 and 12+(11)=112 + (-11) = 1):

(n11)(n+12)=0(n - 11)(n + 12) = 0

Apply the Zero Product Property and solve each equation:

n11=0orn+12=0n - 11 = 0 \quad \text{or} \quad n + 12 = 0

n=11orn=12n = 11 \quad \text{or} \quad n = -12

Because there are two values of nn, two pairs of consecutive integers satisfy the condition:

  • If n=11n = 11, then n+1=12n + 1 = 12, giving the pair 11 and 12.
  • If n=12n = -12, then n+1=11n + 1 = -11, giving the pair 12-12 and 11-11.
  1. Check: 1112=13211 \cdot 12 = 132 ✓ and (11)(12)=132(-11)(-12) = 132 ✓.
  2. Answer: The consecutive integers are 11, 12 and 12-12, 11-11.

Unlike consecutive-integer problems involving sums — which produce linear equations — problems involving products lead to quadratic equations. Because a quadratic equation can yield two solutions, there may be two valid pairs of consecutive integers. Here, a negative pair also works because multiplying two negative numbers produces a positive product.

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Updated 2026-04-21

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