Max is paid a salary of $225 a week plus %2.5 commission on his total sales. what was max's total sales for the week if he made a total of $4,650 in sales?

So we know he made 4,650 of sales and we need 2.5% of that

First to find 2.5% of 4650 we could do 

x/4650 = 2.5/100 
 Cross multiply to get

100x = 11625
x = 116.25

So his salary for this week would be 225 + 116.25 = 341.25

Polar coordinates is 8,9