Do 5.4 plus 5.8 then do 3.4w minus 1.8w and whatever you get for each is your key to the expression. So if you were to solve the answers like A you would do 7(1.6+w) and see what you would get. Obviously A isn't the answer. Sorry, this is hard to explain. But the answer is C
Consider,

. Let's say

then the problem reduces to

. (Do you understand this step?)
So then replacing a again with our definition we get,

.
Answer:
i did it again i did i did not do did it
When line is parallel to y axis
Answer
Rectangle or Square
Why
Only square and rectangle has the property of having a 2 90 degrees angle or right angle.