Math Problem Statement

a^2+b^2=25 a+b=7

Solution

We are given two equations:

  1. a2+b2=25a^2 + b^2 = 25
  2. a+b=7a + b = 7

To solve for aa and bb, we can use substitution or elimination. Here's how we can approach it:

Step 1: Express a2+b2a^2 + b^2 in terms of (a+b)2(a+b)^2

We know that:

(a+b)2=a2+2ab+b2(a+b)^2 = a^2 + 2ab + b^2

Using the second equation a+b=7a + b = 7:

72=a2+2ab+b27^2 = a^2 + 2ab + b^2 49=a2+2ab+b249 = a^2 + 2ab + b^2

Now substitute a2+b2=25a^2 + b^2 = 25 from the first equation into this expression:

49=25+2ab49 = 25 + 2ab

Step 2: Solve for abab

Subtract 25 from both sides:

24=2ab24 = 2ab

Divide by 2:

ab=12ab = 12

Step 3: Solve the quadratic equation

Now that we have both a+b=7a + b = 7 and ab=12ab = 12, we can treat aa and bb as the roots of the quadratic equation:

x2(a+b)x+ab=0x^2 - (a+b)x + ab = 0

Substitute a+b=7a+b = 7 and ab=12ab = 12:

x27x+12=0x^2 - 7x + 12 = 0

Step 4: Factor the quadratic equation

Factor the quadratic:

(x3)(x4)=0(x - 3)(x - 4) = 0

So, x=3x = 3 or x=4x = 4.

Step 5: Conclusion

Therefore, the values of aa and bb are a=3a = 3, b=4b = 4 (or vice versa: a=4a = 4, b=3b = 3).


Would you like more details on any part of this solution?

Here are 5 related questions:

  1. How do you solve quadratic equations by factoring?
  2. Can we solve this system using substitution instead of factoring?
  3. What happens if we change the constants in the equations, such as a2+b2=36a^2 + b^2 = 36?
  4. How do we solve a system of nonlinear equations graphically?
  5. How can the quadratic formula be applied to this system?

Tip: Always check your solution by substituting the values of variables back into the original equations.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Systems of Equations

Formulas

(a + b)^2 = a^2 + 2ab + b^2
Quadratic equation: ax^2 + bx + c = 0

Theorems

Factoring Quadratics
Properties of Systems of Nonlinear Equations

Suitable Grade Level

Grades 8-10