Express 8+11+14+17+20 using sigma notation?

There is a line with slope 1/a going through the point (a, a²). find the equation of the line perpendicular to this line at this point. (don’t let this problem intimidate you! solve the problem as you would if i’d given you specific values. just use variables instead.)

Ben is three times as old as samantha, who is two years older than half of michel's age. if michel is 12. how old is ben?

Create a data set with 8 points in it that has a mean of approximately 10 and a standard deviation of approximately 1.