x(x + (12 - x)) = 72 - United Radiology

April 21, 2026 · United Radiology

["Solving x(x + (12 - x)) = 72: A Complete Step-by-Step Guide", "Mathematics often presents problems that look complex at first but become straightforward with the right approach. One such intriguing equation is:", "x(x + (12 - x)) = 72", "At first glance, this equation may appear subtle, but solving it reveals fundamental algebraic principles and useful techniques. In this article, we’ll explore how to simplify, solve, and understand the solution to this elegant equation — and why it’s more than just homework practice.", "---", "### What Is the Equation?", "The equation in focus is:", "[
\nx(x + (12 - x)) = 72
\n]", "It involves a variable x nested inside a binomial expression. Simplifying it reveals key insights about linear relationships and quadratic structure.", "---", "### Step 1: Simplify the Expression Inside Parentheses", "Start by simplifying the inner expression inside the parentheses:", "[
\nx + (12 - x) = x + 12 - x = 12
\n]", "This simplification is exciting — the variable x cancels out, leaving a constant.", "---", "### Step 2: Substitute Back Into the Equation", "Now substitute the simplified expression back:", "[
\nx \cdot 12 = 72
\n]", "Which simplifies cleanly to:", "[
\n12x = 72
\n]", "---", "### Step 3: Solve for x", "Divide both sides by 12:", "[
\nx = \frac{72}{12} = 6
\n]", "---", "### Final Answer", "The solution is:
\n[
\n\boxed{x = 6}
\n]", "---", "### Why This Equation Matters: Real-World and Conceptual Insights", "While x = 6 solves the equation directly, this type of problem demonstrates:", "- Algebraic cancellation: The surprising cancellation of x in the original expression teaches how symmetry and simplification reveal underlying structure.
\n- Quadratic readiness: Though the equation simplifies to a linear form, forming and simplifying such expressions builds foundational skills for solving quadratic equations.
\n- Verification: Always verify your solution by plugging x = 6 back into the original equation:
\n [
\n 6(6 + (12 - 6)) = 6(6 + 6) = 6 \cdot 12 = 72 \quad \ ext{(Correct!)}
\n ]", "---", "### Practical Applications", "Equations like this appear in:", "- Geometry: Calculating dimensions where linear relationships govern total area or perimeter.
\n- Economics: Modeling profit margins or cost functions with fixed and variable components.
\n- Everyday problem-solving: Balancing variables under constraints.", "Mastering simplification and substitution here empowers learners to tackle complex real-world math challenges with confidence.", "---", "### Summary", "The equation
\n[
\nx(x + (12 - x)) = 72
\n]
\nsimplifies elegantly due to variable cancellation inside the parentheses, leading to a clear linear solution:
\n[
\nx = 6
\n]
\nUnderstanding such patterns strengthens algebraic intuition and problem-solving skill across math domains.", "---", "### Keywords for SEO Optimization
\n- x(x + (12 - x)) = 72
\n- math equation solution
\n- algebra simplification
\n- solve linear equations
\n- step-by-step algebra
\n- quadratic readiness
\n- cancel x algebra
\n- verify solution math
\n- educational algebra practice", "---", "Try solving similar equations yourself — you’ll soon recognize the pattern every time!
\nUnderstanding how substitution and cancellation simplify expressions is vital, whether in school, standardized tests, or real-world modeling."]

Related Articles

Trending Articles

Archive