Solve the following system by the substitution method. check the solution.
3x+6y=4x
x=8-2y
select the correct choice below and, if necessary, fill in the answer box to complete your choice.
a.
the system has a single solution. the solution set is ( , )
type an ordered pair.)
b.
there are infinitely many solutions. the solution set is (3x+8y=4x)(x, y)
(type your answer in standard form.)
c.
the solution set is the empty set.