I am so confused can someone please help me :)

Which of the following is the equation of a line that passes through the point (1,4) and is parallel to the x-axis a. y=1 b. y=4 c. x=1 d. x=4

The variable z is directly proportional to x, and inversely proportional to y. when x is 4 and y is 13, z has the value 1.2307692307692. what is the value of z when x= 9, and y= 20

Consider the system: y = 3x + 5 y = ax + b what values for a and b make the system inconsistent? what values for a and b make the system consistent and dependent? explain