Which system of equations is best represented by this graph? 3x-y=2 4x+9y=36 3x-y=6 4x+9y=4

Given that (x-3) is a factor of f(x)=x^3+ax^2-x-6, find a and hence the number of real roots or the equation f(x)=0

Asimple random sample of size nequals14 is drawn from a population that is normally distributed. the sample mean is found to be x overbar equals 70 and the sample standard deviation is found to be sequals13. construct a 90% confidence interval about the population mean

Will give brainliest sum of arithmetic series (sigma notation) find the numerical answer to the summation given below. (image shown below)