Solve the System by the Best Method $$\left\{ \begin{array} { c } x + 8 y = - 61 \\8 x + 7 y = - 89\end{array} \right.$$

question 71

Multiple Choice

Solve the system by the best method. Use set notation to express the solution set.
- $$\left\{ \begin{array} { c } x + 8 y = - 61 \\8 x + 7 y = - 89\end{array} \right.$$

• A) no solution; \(\varnothing\)
• B) \(\{ ( - 5 , - 7 ) \}\)
• C) \(\{ ( 5 , - 6 ) \}\)
• D) \(\{ ( - 6 , - 6 ) \}\)

---

Definitions:

Demand Curve

A graphical representation of the relationship between the price of a good and the quantity of the good that consumers are willing to buy.

Marginal Cost

The increment in cost due to the manufacture of an additional product or service unit.

Price Elasticity

A concept related to elasticity of demand, specifically measuring how much the quantity demanded of a good responds to changes in its price.

Marginal Cost

The expenditure associated with creating a subsequent unit of a product or service.