Step-by-step explanation:
Let x be the price of an apple and y be the price of an orange.
We have been given that a fruit stand need $10 for 4 apples and 4 oranges. We can represent this information as:

We are also told that they need $15 for 6 apples and 6 oranges. We can represent this information as:
Therefore, our desired system of equations will be:


Answer:
66
Step-by-step explanation:
If there are <em>n</em> students, then the number of pairs is
.
With 12 students,
pairs can be formed.
The reason the formula works is this: Each of the 12 students can be paired with 11 other students (no student is paired with him/her self). But counting 12 x 11 = 132 counts each pair <u>twice</u>. Example: student A can be paired with student B,..., student B can be paired with student A. The pair was counted two times.
See the attached image that shows pairings of 5 students. There are
5(5 - 1)/2 = 5(4)/2 = 10 pairs.
The answer to your question is 92
The 9 stands for hundredths