Find the number of ful 8 hour shifts that Maria worked last month.
1) She worked twice as many 6 hour shifts as 8 hour shifts.
2) She worked a total of 280 hours.

How do we solve??

I'm going to try not to give too much away. Part of what you shoud be learning is HOW to think about these word problems... not just the math. That HOW may be different for you and me but in any case it takes some practice... or it did for me.

Consider: How would you solve if it was simply asking for the number of 8 hour shifts to get 280 hours? x, let's say, being equal to the number of shifts

Now write line 1.) in terms of x

Think about it and write and solve the full formula.