Math Problem Statement

the sum of two numbers is 30. Their product is 176. What are the two numbers?

Solution

Let's denote the two numbers as xx and yy.

We are given two key pieces of information:

  1. The sum of the two numbers: x+y=30x + y = 30

  2. The product of the two numbers: xy=176xy = 176

We can solve this system of equations by first expressing one variable in terms of the other from the sum equation.

From x+y=30x + y = 30, we can express yy as: y=30xy = 30 - x

Now, substitute this expression for yy into the product equation: x(30x)=176x(30 - x) = 176 Expanding and rearranging the equation: 30xx2=17630x - x^2 = 176 x230x+176=0x^2 - 30x + 176 = 0

This is a quadratic equation in the standard form ax2+bx+c=0ax^2 + bx + c = 0, where a=1a = 1, b=30b = -30, and c=176c = 176.

We can solve this quadratic equation using the quadratic formula: x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} Substituting the values: x=(30)±(30)24(1)(176)2(1)x = \frac{-(-30) \pm \sqrt{(-30)^2 - 4(1)(176)}}{2(1)} x=30±9007042x = \frac{30 \pm \sqrt{900 - 704}}{2} x=30±1962x = \frac{30 \pm \sqrt{196}}{2} x=30±142x = \frac{30 \pm 14}{2}

So, the two possible solutions for xx are: x=30+142=442=22x = \frac{30 + 14}{2} = \frac{44}{2} = 22 or x=30142=162=8x = \frac{30 - 14}{2} = \frac{16}{2} = 8

Thus, the two numbers are 22 and 8.

Verification

  • Sum: 22+8=3022 + 8 = 30
  • Product: 22×8=17622 \times 8 = 176

Both conditions are satisfied.

Final Answer:

The two numbers are 22 and 8.

Would you like more details or have any questions?

Here are five related questions:

  1. How can we solve quadratic equations using factoring?
  2. What is the discriminant in a quadratic equation, and how is it used?
  3. Can you find the roots of the quadratic equation using the completing the square method?
  4. How do we derive the quadratic formula from a general quadratic equation?
  5. What are the applications of quadratic equations in real-world problems?

Tip: Always check your solution by substituting the values back into the original equations to ensure they satisfy all given conditions.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Systems of Equations

Formulas

Quadratic formula
Sum and product relationships

Theorems

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Suitable Grade Level

Grades 9-12