Solve the System by the Substitution Method $$\left\{ \begin{array} { r r } 9 x + y = & 0 \\- 9 x + y = & - 18\end{array} \right.$$

question 74

Multiple Choice

Solve the system by the substitution method.
- $$\left\{ \begin{array} { r r } 9 x + y = & 0 \\- 9 x + y = & - 18\end{array} \right.$$

• A) \(\varnothing\)
• B) \(\{ ( 1 , - 9 ) \}\)
• C) \(\{ ( x , y ) \mid 9 x + y = 0 \}\)
• D) \(\{ ( - 1,9 ) \}\)

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Definitions:

Perpetual System

An inventory management system that records sales and purchases of goods instantly through computerized systems to maintain accurate inventory levels at all times.

Revenue Side

Refers to the income-generating aspects of a business, focusing on activities that bring revenue into the company.

Sales Discounts

Reductions in the selling price offered to customers as incentives to encourage prompt payment.

Cash Discount

A reduction in the invoice price offered by sellers to buyers as an incentive for early payment within a specified period.