Andre and Elena are solving this system of equations: y=3x, y=9x−30

Andre's first step is to write: 3x=9x−30
Elena’s first step is to create a new system: {3y=9xy=9x−30
Do you agree with either first step? If so which one and explain your reasoning

Analyze the data sets below. data set a 25,25,25,26,26,26,27,28,28,29,30,31 ,31,32,33,33,34,35,35,35 data set b 25,25,25,26,26,26,26,27,27,27,27,28 ,28,29,29,30,31,31,32,34 which of the following statement are true? select all that apply. a. data set a is relatively symmetric and data set b is skewed left. b. the means of the data sets are within 3 units from eachother. c. the data sets have the same standard deviation. d. the mean of data set a is 27.95 and the mean of data set b is 30. e. the data set b has a higher standard deviation than data set a. f. the mean and median of data set a are close in value.

To finance her community college education, sarah takes out a loan for $2900. after a year sarah decides to pay off the interest, which is 4% of $2900. how much will she pay

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25