The answer to the problem is c
3(y-1)=y-11
Distribute:
3y - 1 = y- 11
Add 11 to both sides
3y - 12 = y
subtract 3y on both sides
-12 = -2y
Divide by 2y
y= 6
100 have smoked at last once
If the problem was written x + 4x. We would know to add like the coefficients together and get 5x same thing with the radicals.
What you do is - 82400 from 102650 and you should get your answer