Answer:

Step-by-step explanation:
Lowest common denominator for 3,4,6 is 12
5/6 = 10/12
1/4 = 3/12
2/3 = 8/12
a)
10/12 + 3/12 = 13/12 = 1 1/12
So you need to use first and second cables
b)
3/12 + 8/12 = 11/12
To reach 1 yard Carl need 1/12 yard cable
7(200 + 50 + 6) = (7 x 200) + (7 x 50) + (7 x 6) = 1,400 + 350 + 42 = 1,792
I think the pattern is
++_0_--
i.e positive twice neutral negative twice
2010
0.00 and 2012
-0.45