Answer:
-5/8
Step-by-step explanation:
13/ -56 -x = 11/28
Add 13/56 to each side
13/ -56 + 13/56 -x = 11/28+ 13/56
-x = 11/28 + 13/56
Get a common denominator
-x = 11/28 *2/2 +13/56
-x = 22/56 + 13/56
-x = 35/56
Divide top and bottom by 7
-x = 5/8
Multiply both side by -1
x = -5/8
By inclusion/exclusion,

We have

so that

Now,

and by inclusion/exclusion,

Decompose
into the union of two disjoint sets:

Since they're disjoint,




From the Venn diagram, we see there are 3 elements unique to
- by the way, this is the set
- so
, and it follows that

Finally, we get for (a)

For (b), we have by inclusion/exclusion that

First Play: loses 5 yards ( -5 )
Second Play: loses 15 yards ( -15 )
Third Play: gains 12 yards ( +12 )
-5yd + (- 15yd) + 12yd
= -20yd + 12yd
= -8yd
Answer:
12e+7f
Step-by-step explanation:
you gather like terms
5e+7e =12e
8f-f=7f
12e + 7f