What is the solution of the system of equations?
y = 3x + 7
y = x – 9
a. (–8, –17)
b. (–1, –10)
c. (–17, –8)
d. (4, 19)

y = 5x – 4
y = 5x – 5
a. no solutions
b. one solution
c. infinitely many solutions