Answer:

Step-by-step explanation:
To solve this question, we will first expand the expression using the distributive rule: 
Therefore:

Simplify:

Add up like terms:

Answer:
2
Step-by-step explanation:
the y-intercept is where the line meets the y-axis
I'd say this high concentration is due to geological processes
Geological processes are things such as erosion, tectonic plate shifts, e.t.c.