How do you solve this with the fractions?

5(-9w) put expression in distributive property

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?

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. 4x^2 + 20x + 25 = 0