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:it y
Step-by-step explanation: it y =2/2x-3
For x = -1, 3(-1) - 5y = 9 => -3 - 5y = 9 => 5y = -3 - 9 = -12 => y = -12/5 = -2.4
for x = 0, 3(0) - 5y = 9 => -5y = 9 => y = 9/-5 = -1.8
for x = 1, 3(1) - 5y = 9 => 3 - 5y = 9 => 5y = 3 - 9 = -6 => y = -6/5 = -1.2
It causes the breakdown and decay to the rocks. It occurs when the weather water is slightly acidic.