U = - 4 i + 1 j
v = 4 i + 1 j
| u | = √ (-4)² + 1² = √ 17
| v | = √4² + 1² = √ 17
| u + v | = √(u + v)²=
= √( u² + 2 u v + v² )= ...
cos ( u, v ) = (-16+1) / (|u| |v|) = -15/17
...= √(17 + 2 · √17 · √17 · ( -15/17) +17) =
= √ 34 - 30 = √ 4 = 2
Answer: C ) 2
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 Newton's Law of Gravity is a mathematical model of gravitation, originally a theory, verified by observation, and now superseded by the General Theory of Relativity.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.
I Think The answer is a I hope it helps My friend Message Me if I’m wrong and I’ll change My answer and fix it for you
Answer: <span>D. Are perpendicular
</span><span>4x=3y+23 slope = 4/3
</span><span>4y+3x=-19 slope = -3/4</span>
The correct answer Is D. Purple , Green , Yellow
Hope I helped! ( Smiles )