Solve the system
{3x-y=4
-9x+3y=-12

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.

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

The graph below represents the number of dolphins in a dolphin sanctuary. select all the key features of this function.