If there were only sandwiches bought, there would be 15, if there were only salads bought there would be 20. There’s probably more than one possibility, but that’s the best I can do, considering how long it’s been since I’ve done this type of problem. I’m all the way to learning determinants, so I really have to think to remember these. Sorry in advance if this doesn’t help at all, I’m not the best at this, but I can still try.
78, because you have to do the inverse operation so 80/2= 40 then 40-1= 39 and 39*3 = 78
Answer: 
Step-by-step explanation:
Observe in the figure given in the exercise that four right triangles are formed.
In this case you can use the following Trigonometric Identity to solve this exercise:
From the figure you can identify that:

Then, you can substitute values:

The next step is to solve for DE in order to find its value. This is:

Finally, rounding the result to the nearest tenth, you get that this is:

Answer:
x = 2
Step-by-step explanation:
(16 =
and 8 =
)

Since the base number is 2, the exponents must equal each other.
So:
12x = 3x+18
9x = 18
x = 2
Answer:
8 days
Step-by-step explanation:
4/5= 8/10