Solution:
iv) Given equation: 
Since we are given two variables, we need to split the original expression into two quadratic expressions as

Factoring x first:

= 
= 

Factoring y now:

= 
= ![-1[ y(y+1) + 1(y+1)]](https://tex.z-dn.net/?f=-1%5B%20y%28y%2B1%29%20%2B%201%28y%2B1%29%5D)
= ![-1 [(y+1)(y+1)]](https://tex.z-dn.net/?f=-1%20%5B%28y%2B1%29%28y%2B1%29%5D)
= 
Therefore, the original expression becomes

Answer:
I got 0.00001693508 is that one of your answers?
Answer:
75. by angle sum property of an traingle
(7,0) i think. i’m not sure so check