Yes.
Yes.
Yes it is a function. In standard form it is y=x-4.
y(x) = (4 - x)/4.
Indeed, these two equations are the same - because addition is a commutative function.
The vertex is at the point (0, 4).
4+1=5. Plus 4 equals 9. Plus 77685769844446473 equals 77685769844446482. Plus 3 equals 77685769844446485. Plus 8 equals 77685769844446493. Plus 1 equals 77685769844446494. Plus 9870998342523322424 equals 1064785604097768918. Plus 4 equals 1064785604097768922.
If 2x + 3y = 4, y= (4 - 2x)/3. In function notation, f(x) = (4 - 2x)/3.
All of them
1 plus 1 plus 1 plus 1 equals 1 times 4. 1 times 4 equals 4. 4 minus 4 equals 0. 0
8x6 plus 4 equals 52.
-4 plus 10 equals 6.