I don't really get this question but simply put, if you are in college syntax matters very much. (13-4) = 9 *(x-5) = 9x-45.. although in this case. since there isn't a bracket around 13-4. you'd multiply by the -4 first, giving you, 4x-20+30 =4x-10
Sorry it took so long, here is your answer:
Y = 9
7y - 10y = -3y
bring down the 9 = -18 so
-3y + 9 = -18
9 - 9 = 0
- 18 - 9 = - 27
- 3y ÷ - 3 = y
- 27 ÷ -3 = 9
therefore y =9
All three numbers have to have a equal multiple.