Asegment has endpoints with coordinates (a,2b) and (-3a,4b). write the coordinates of the midpoint of the segment in terms of a and b

Yesterday i ran 5 miles. today, i ran 3.7 miles. did my percent increase, decrease or is it a percent error? plz i need

Avery’s piggy bank has 300 nickels, 450 pennies, and 150 dimes. she randomly picks three coins. each time she picks a coin, she makes a note of it and puts it back into the piggy bank before picking the next coin.

If the average of x, y and z is 15 what is their sum