Does the table below represent a linear or nonlinear function?

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?

Mat bought a phone for $100. he has to pay $30 per mouth. if he has paid $640 in total, how many mouth has he had the phone?

Me! i will mark brainliest! i don't get polynomials and all that other stuff. so this question is really hard. multiply and simplify.(x - 4) (x^2 – 5x – 6)show your