You would use distribution. So, in this case, it would be 10a - 50. You use -10 to multiply -a and 5, and you get 10a, and -50.
First, you add like terms. In this case, the like terms are 6 and 3.
4x + 6 + 3 = 17
4x + 9 = 17
Then, subtract 9 on each side:
4x + 9 - 9 = 17 - 9
4x = 8
Then divide by 4 on each side to get the x by itself:
4x/4 = 8/4
x = 2
Y = 12x where x is the # of students and y is the # of adults
Or for every 12 students there's 1 adult
The amount of interest Molly will earn after 5 years on a deposit of
compounded annually over 5 years is 
First, we need to find the future value of her investment, then we subtract the original deposit from it to get the amount of interest she will get at the end of 5 years.
The future value of an investment that is compounded annually is given by

where

Substituting the available values into the formula and solving

The interest Molly will earn after 5 years is

Therefore, the amount of interest Molly will earn after 5 years on a deposit of
compounded annually over 5 years is 
Learn more about compound interest here: brainly.com/question/21270833
Thank you very much and this “question” was very helpful for me.