All you have to do is try out both of the equations with each of the different choices.
200 = 45 (3) + 20
200 = 135 + 20
200 = 155
200 = 35 (3) + 60
200 = 105 + 60
200 = 165
So, this one does not work.
--------------------------------------------
180 = 45 (3) + 20
180 = 135 + 20
180 = 155
180 = 35 (3) + 60
180 = 105 + 60
180 = 165
So, this one does not work.
----------------------------------------------
200 = 45 (4) + 20
200 = 180 + 20
200 = 200
200 = 35 (4) + 60
200 = 140 + 60
200 = 200
So this one works.
The answer would be C.
I hope this helps and I'm sorry it took so long!

The demoin is all real numbers greater than 6
What I would do:
5x + 10y = 35
Divide everything by 5.
x + 2y = 7
x = 7 - 2y
Now plug "x" into either one of the equations.
2(7-2y) + 5y = 15
14 - 4y + 5y = 15
14 + y = 15
y = 1
Now, solve for x by plugging in y into either one of the equations.
2x + 5y = 15
2x + 5 =15
2x = 10
x = 5
So x is 5 and y is 1.
Check by plugging in the values into the other equation.
5x + 10y = 35
5(5) + 10(1) = 35
25 + 10 = 35
35 = 35
The values are correct so, the answer for this problem is B (5, 1).