Multiples of 3 between 6 and 30

Simply 8x squared + 5(7x squared- x) - 2x =

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

Select the margin of error that corresponds to the sample mean that corresponds to each population: a population mean of 25, a standard deviation of 2.5, and margin of error of 5%