Question: A sustainable infrastructure project requires materials costing $ 3x + 5y $ dollars and $ 2x - y $ dollars. If the total cost is $ 20 $ dollars and $ x = 2 $, find $ y $.

Wed, 06 May 2026 07:25:25 +0000

**Why Sustainable Infrastructure Investments Are Reshaping U.S. Development — and How You Can Understand Them** In a nation increasingly focused on climate resilience and long-term economic stability, innovative models for sustainable infrastructure are gaining momentum. From green urban planning to smart energy integration, projects balancing cost, materials, and environmental impact are emerging as critical to future growth. At the heart of this shift lies a mathematical challenge: optimizing complex material costs in ways that deliver both efficiency and sustainability. One such challenge, rooted in real-world planning, asks: If a project’s material costs follow formulas $ 3x + 5y $ and $ 2x - y $, and the total is $20 when $x = 2$, what does $y$ reveal about hidden budget dynamics? This question isn’t just theoretical — it reflects growing demand for transparent, data-driven infrastructure planning across industries. As climate-focused initiatives expand, understanding how cost equations inform real-world decisions matters more than ever. **The Context: Why This Cost Model Matters Now**