Answer: x + 30 + 90= 180(sum of angles on a straight line)
x= 180-120
x=60
There are 14 possibilities for first place.
There are 13 possibilities for second place, since a dog can't get both first and second place.
There are 12 possibilities for third place, since a dog can't get both first, second, and third place.
There are 11 possibilities for fourth place, since a dog can't get both first, second, third, and fourth place.
Multiply them together and get 24024 possibilities.
Hope this helps!
Answer:

multiply all terms in the top equation by 2
multiply all terms in the second equation by -7. it would then add the two equations together to cancel out the variable x
You will then have two equations in terms of y
solve for y and either equation then substitute that value for y into the other equation then solve for x
That answer is A
5/1
Which is
1
1
1
1
1