Equation: (70 + 70*.05) + (580 + 580*.07) + (620 + 620*.10) = Total Spent
Solving for this gets you $1320.30.
The unit price is $1.23 (I think!!)
To solve your question, you add all of the measurements together, set them equal to 180, solve for x, and plug x back in for whichever angle they are asking for; in this case, they want angle R
7x + 12x + 20 + 20x - 35 = 180
39x - 15 = 180
39x = 180 + 15
39x = 195
x = 5
Angle R = 12x + 20
12(5) + 20
60 + 20
80
Option C is your answer.
E is the answer I am pretty sure.
I believe the answer is (-1,1) . The origin is the same as (0, 0) so I drew the line on a quick graph and if you are talking about distance, then the answer should be correct.
Hope this helped :)