Step-by-step explanation:
jhggcxddddddddddddddddd
The diameter of the circle is 10.86
Knowing that there are two logs on both sides of the brackets, they cancel out.
This leaves:
4y-1=2y+7 (solve for y)
4y-2y=7-1
2y=6
y=3
Hope this helped :)
The equation is a scientific law, Newton's Law of Gravity,

This is a pretty bad question. Newton's Law of Gravity is a mathematical model of gravitation, originally a theory, verified by observation, and now superseded by the General Theory of Relativity.
C is probably the best answer to this poor question.