520 CD's because of the 9 months and we add 30 time 9 we erase the 0 and multiply the 3 with the 9 it will be 27 right we add the zero because the originla number is 30
The fraction is 36/42.
36 + 42 = 78
36/42 = 6/7
X + x + 36 = 90
2x = 54
x = 27 Answer
Answe: 3rd one
Step-by-step explanation:
