Answer:
See explanation
Step-by-step explanation:
We want to verify that:

Verifying from left, we have

Expand the perfect square in the right:

We expand to get:

We simplify to get:

Cancel common factors:

This finally gives:

Answer:
The explicit formula

The recursive formula
for 
if 
Step-by-step explanation:
If a sequence is arithmetical then the difference between any of its consecutive terms will be constant
3, 3.25, 3.5, 3.75,

The difference between the consecutive terms remains constant so the sequence is arithmetic.
The explicit formula for an arithmetic sequence is:

Where d is the constant difference between the terms.

is the first term of the sequence.

So

Finally, the recursive formula is:

3x+3-x+(-7)>6
combine like terms on left side
2x-4>6
add 4 to both sides 2x>10
x=10/2 = 5
x>5
It’s four because you subtract 2 minus negative 2
You can use the vertical line test (the blue lines on the drawing) and if the other end or if any part of the line touches the blue line, then it isn’t a function.