A student performed row operations on a matrix as shown below. -4
1 2
4
4
-4
1
2
4
-1 3
1
→
0
-1 3
1
3
4
4
5
3
0
107
N
Which operations did the student perform?
2R2+ R3 R3
2R3+-R3 R3
2R2+R3 R2,R3
2R2 R3

The number of hours per week that the television is turned on is determined for each family in a sample. the mean of the data is 37 hours and the median is 33.2 hours. twenty-four of the families in the sample turned on the television for 22 hours or less for the week. the 13th percentile of the data is 22 hours. approximately how many families are in the sample? round your answer to the nearest integer.

Jackie purchased 3 bottles of water and 2 cups of coffee for a family for $7.35. brian bought 4 bottles of water and 1 cup of coffee for his family for $7.15. how much does each bottle of water cost? how much does each cup of coffee cost? i need this done

Adj has a total of 1075 dance and rock songs on her system. the dance selection is 4 times the size of the rock selection. write a system of equations to represent the situation.