-Y(3x+y) - (21-Y) expand and simplify ​

According to the normal model, what percent of receivers would you expect to gain fewer yards than 2 standard deviations below the mean number of yards

Jordan rides his bike 6 7/15 miles every day to deliver newspapers and to go to and from school. if his ride to and from school is 4 3/10 miles, how many miles is the trip to deliver newspapers? 1 1/3 1 1/6 2 1/6 2 4/5

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)