Plea ! 40 points to whoever answers righ

Which of the following expressions is equal to 2x^2+8

Find the constant of variation for the relation and use it to write an equation for the statement. then solve the equation.

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?