Answer:
D. 35 + 145 = x
The sum of the angles = 180 degree
Step-by-step explanation:

So you want to start to factor so you get (x²+2)(x²-7) = 0. Now set each () to 0, so you get (x²+2) = 0 and (x²-7)=0. The first ends with +√2i and -√2i, the second ends with +√7 and -√7
P = 2l + 2w
Subtract both sides by 2w
P - 2w = 2l
Divide both sides by 2
(P - 2w) / 2 = l
In our problem,
w = 7 in
P = 42 in
Let's plug our values into the formula above.
(42 in - 2(7 in) / 2 = l
(42 in - 14 in) / 2 = l
28 / 2 = l
14 in = length