Select all the systems of equations that have exactly
one solution.
y = 3x + 1
y =− 3x + 7

y = 3x + 1
y = x + 1


y = 3x + 1
y = 3x + 7


y =− x + 10
y =− 1x + 10



y =− x + 10
y =− x + 12