经济学家使用均衡这个术语来描述市场中供需之间的平衡。在理想的市场条件下，当产量满足客户对该商品或服务的需求时，价格趋于稳定在稳定的范围内。均衡易受内部和外部影响。破坏市场的新产品（如iPhone）的出现就是内部影响力的一个例子。作为大萧条的一部分，房地产市场的崩溃是外部影响的一个例子。通常，经济学家必须通过大量数据来解决平衡方程。本分步指南将向您介绍解决此类问题的基础知识。市场中的均衡价格和数量位于市场供给曲线和市场需求曲线的交叉点。虽然以图形方式查看这一点很有帮助，但在给定特定供需曲线时，能够以数学方式求解均衡价格P *和均衡数量Q *也很重要。供给曲线向上倾斜（因为供给曲线中P上的系数大于零），需求曲线向下倾斜（因为需求曲线中P上的系数大于零）。市场中的均衡发生在该市场供应的数量等于该市场所需的数量的地方。因此，我们可以通过设定供给和需求相等然后求解P来找到均衡。此外，我们知道在基本市场中，消费者为商品支付的价格与价格相同。生产者得到了好处。因此，供给曲线中的P必须与需求曲线中的P相同。由于P *和Q *表示在给定价格下供应量和需求量相同的条件，实际上，P *和Q *图形地表示供需曲线的交点。将您在代数上找到的均衡与图形解决方案进行比较通常很有帮助，以便仔细检查是否没有计算错误。
Economists use the term equilibrium to describe the balance between supply and demand in the marketplace. Under ideal market conditions, price tends to settle within a stable range when output satisfies customer demand for that good or service. Equilibrium is vulnerable to both internal and external influences. The appearance of a new product that disrupts the marketplace, such as the iPhone, is one example of an internal influence. The collapse of the real estate market as part of the Great Recession is an example of an external influence. Oftentimes, economists must churn through massive amounts of data in order to solve equilibrium equations. This step-by-step guide will walk you through the basics of solving such problems. The equilibrium price and quantity in a market is located at the intersection of the market supply curve and the market demand curve. While it is helpful to see this graphically, it’s also important to be able to solve mathematically for the equilibrium price P* and the equilibrium quantity Q* when given specific supply and demand curves. The supply curve slopes upwards (since the coefficient on P in the supply curve is greater than zero) and the demand curve slopes downwards (since the coefficient on P in the demand curve is greater than zero). The equilibrium in a market occurs where the quantity supplied in that market is equal to the quantity demanded in that market. Therefore, we can find the equilibrium by setting supply and demand equal to one another and then solving for P. In addition, we know that in a basic market the price that the consumer pays for a good is the same as the price that the producer gets to keep for the good. Therefore, the P in the supply curve has to be the same as the P in the demand curve. Since the P* and Q* represent the condition where quantity supplied and quantity demanded are the same at a given price, it is, in fact, the case that P* and Q* graphically represent the intersection of the supply and demand curves. It is often helpful to compare the equilibrium that you found algebraically to the graphical solution in order to double check that no calculation errors were made.