Can someone explain quadratic formula to me here are the problems I am having trouble with:

V^2+8v+6=o

-x^2-5x+1=0

2t^2-6t+1=0

I don't know where to begin, also when I'm trying to complete a square such as:

2m^2-m-15=0

where do I start to complete equations is

2x^2+5-1=5

if I am trying to solve this type of equation:

2x^2-1=x squared and it is telling me to look for extraneous solution what is it trying to tell me to look for and where do Ibegin with this type

If I am looking for a perfect square :

3x^2+15+9 do I not need to filter out the GCF forst and make the equation

3(x^2+5+3) ----- and if I do that there is no perfect square please inform

Trying to solve with formulas where would you start:

Example ---- v=4/3(pi)r^2h and I'm trying to solve for h where again do I begin

Solving proportions:

-5/9=3/x or 9/3=3/2

am I correct in saying that the answers are -----x= -27/5 and x= 6

If i have 2m/3 = 3m/2

Is my answer:

4m=9m

9m-4m=0

5m=0

m=0