Identify the solution for the following.

Solve for the system of equations using substitution.
 $4x\ +\ y\ =\ 8$  
 $x=5\ -\ y$  

Solve for the system of equations using substitution.
 $y\ =\ 4-2x$  
 $-4x-2y=-8$  

Solve for the system of equations.
 $y\ =\ 5x+1$  
 $y=-3x-15$  

Solve for the system of equations. 
 $y\ =\ 7-3x$  
 $y=2x-8$  

Solve for the system of equations using substitution.
 $y\ =\ 2x-3$  
 $-2x+y=1$  

When solving a system of equations algebraically, which statement results in infinite solutions?

When solving a system of equations algebraically, which statement results in no solution?

What is the first step in the substitution method?