Answer:
Step-by-step explanation:
Direct variation:
mathematical relationship between two variables that can be expressed by an equation in which one variable is equal to a constant times the other.
(y varies directly with x with a constant variation of k)
[tex]y=kx;\ k\neq0[/tex]
[tex]y=kx\qquad|\text{divide both sides by}\ x\\\\\dfrac{y}{x}=k\Rightarrow \dfrac{y}{x}=constant[/tex]
[tex]21.\\\\x=y+2\qquad|\text{subtract 2 from both sides}\\\\x-2=y\qquad|\text{divide both sides by}\ x\\\\1-\dfrac{2}{x}=\dfrac{y}{x}\ro\dfrac{y}{x}=1-\dfrac{2}{x}\neq constant[/tex]