To answer this question we will have to keep the following two points in mind:
#1. The sum of a number with another number means to add the given two numbers.
#2. Twice means to multiply by 2. In other words it means to double.
Therefore, "twice the sum" would mean to multiply the sum by 2.
Now, in our question we will have, "the sum of y and 9 would be: [tex] y+9 [/tex] and twice this sum would be: [tex] 2(y+9) [/tex]
Thus, "twice the sum of y and 9" is: [tex] 2(y+9) [/tex]
