Parametric Equations

Are these equations in parametric or slope intercept form?

$$x=2t-1$$   $$y=t$$  

Is this equation in parametric or slope intercept form?

$$y=2x+3$$  

What is the benefit of having an equation in slope intercept form instead of parametric form?

Convert the equation from parametric to slope intercept

$$x=t+3$$   $$y=t-4$$  

Convert the parametric equation into slope intercept form

$$y=\frac{1}{3}t+2$$  

$$x=\frac{1}{3}t-1$$  

Convert the parametric equation into slope intercept form

$$y=\frac{1}{2}t-5$$  

$$x=\frac{1}{10}t+7$$