Expanding and Simplifying Algebraic Expressions
This article explores the given algebraic equation:
(a + b + c + d)(a - b - c + d) = (a - b + c - d)(a + b - c - d)
We will prove that this equation holds true for any values of a, b, c, and d.
Expanding Both Sides
Let's begin by expanding both sides of the equation using the distributive property (also known as FOIL):
Left Side: (a + b + c + d)(a - b - c + d) = a(a - b - c + d) + b(a - b - c + d) + c(a - b - c + d) + d(a - b - c + d) = a² - ab - ac + ad + ab - b² - bc + bd + ac - bc - c² + cd + ad - bd - cd + d² = a² - b² - c² + d² + 2ad - 2bc
Right Side: (a - b + c - d)(a + b - c - d) = a(a + b - c - d) - b(a + b - c - d) + c(a + b - c - d) - d(a + b - c - d) = a² + ab - ac - ad - ab - b² + bc + bd + ac + bc - c² - cd - ad - bd + cd + d² = a² - b² - c² + d² + 2ad - 2bc
Conclusion
As we can see, both the left and right sides of the equation simplify to the same expression: a² - b² - c² + d² + 2ad - 2bc. Therefore, the equation is true for any values of a, b, c, and d.
This demonstrates a key principle in algebra: expanding and simplifying expressions can help to reveal underlying relationships and prove equations.