Math Problem Statement

The sum of the cubes of two given natural numbers is 9728, while the sum of the two given numbers is 32. What is the product of the two given numbers?

Solution

We are given two natural numbers, say xx and yy, with the following conditions:

  1. The sum of the two numbers is x+y=32x + y = 32.
  2. The sum of their cubes is x3+y3=9728x^3 + y^3 = 9728.

We are tasked with finding the product xyx \cdot y.

Step-by-step Solution:

We know that the identity for the sum of cubes is: x3+y3=(x+y)((x+y)23xy)x^3 + y^3 = (x + y)((x + y)^2 - 3xy) Substitute x+y=32x + y = 32 into the identity: x3+y3=32(3223xy)x^3 + y^3 = 32(32^2 - 3xy) Simplify: 9728=32(10243xy)9728 = 32(1024 - 3xy) Now, divide both sides by 32: 9728÷32=10243xy9728 \div 32 = 1024 - 3xy 304=10243xy304 = 1024 - 3xy Rearrange to solve for xyxy: 3xy=10243043xy = 1024 - 304 3xy=7203xy = 720 xy=7203=240xy = \frac{720}{3} = 240

Thus, the product of the two numbers is 240\boxed{240}.

Would you like more details on any step or have further questions? Here are some related problems:

  1. How do you solve for two numbers given their sum and product?
  2. Can you factor the sum and difference of cubes?
  3. What other identities can be useful for solving cubic equations?
  4. How does the relationship between roots and coefficients work in quadratic equations?
  5. How can the method of substitution help in solving systems of equations?

Tip: When working with identities, it’s useful to remember common formulas like the sum or difference of cubes, as they simplify complex equations quickly.

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Math Problem Analysis

Mathematical Concepts

Algebra
Cubic Equations
Sum of Cubes
Systems of Equations

Formulas

Sum of cubes formula: x^3 + y^3 = (x + y)((x + y)^2 - 3xy)
Sum and product relations: x + y = sum, xy = product

Theorems

Identity for the Sum of Cubes

Suitable Grade Level

Grades 8-10