15/4 plus 11/10
first find the common denominator so the common denominator is 20 so you have turn 10 and 4 to 20.
If you want to turn 4 to 20 you multiply it by 5 you multiply 5 to 4 and 15 that will be 75/20.
if want to turn 10 to 20 you multiply it by 2 . u multiply 2 to 10 and 11 that will be 22/20
then you do 75/20 plus 22/20 you add 75 plus 20 equal 97/20 you don't change the denominator. the decimal will be 4.85.