we have
x=5−2y ---> multiply by 3 both sides-----> 3x=15-6y-----> 6y=15-3x----> equation 1
6y=10−3x------> equation 2
equation 1 and equation 2 has the same slope
the lines are parallel
slope m=-3/6-----> m=-1/2
so
there are no solution
the answer is the option
b. There is no solution