The answer of the question is in the picture.
X = 80
Answer:
opposite sides with equal length
hope it helps

Let f(x) = y
thus y =

switch the position of y and x in the equation

then solve for y in this case

∴ y=

Thus,
171 + 727 = 898.
We can round it off to 900.
Answer:
A) 2p
(because DC is twice the size of AB. Hence why they're in the ratio of 2:1)
B) p+q
(Start from B, go backs against the arrow to the left and get - p, then + q and + 2p. Simplify -p+q+2p)
Hope this helps!