I don’t know what exactly you are trying to ask? But this equation would be an example of exponential growth.
the distance between (8,0) and (1,0) is 7 units
In general, √(y²) = |y|, since y can be positive or negative and y² would have the same value either way.
So,
1) if y > 0, then |y| = y, and
-15√(y²) = -15 |y| = -15y
2) if y < 0, then |y| = -y, and
-√(16y²) = -|4y| = -|4| |y| = -4 (-y) = 4y
