Solve the system of linear equations.
y=x-5
y=-2x+1

I solved this one by substitution. When you are solving for two equations you can do this.
y=x-5
y=-2x+1
substitute the y in one of the equations to find x 
x-5=-2x+1
x=-2x+6
3x=6
x=2
then you plug in that number to one of the equations
y=2-5
y=-3

Iam pretty sure its a sorry if im wrong

Aand b are correctly balanced reactions. they have the same number of atoms in both sides of the reaction