16Hit1600
AlgebraEasyEquation of a horizontal line

Algebra practice question

Which of the following equations has a graph in the xy-plane that is a horizontal line?

  1. A. y = 4Correct
  2. B. x = 4
  3. C. y = 4x
  4. D. y = x + 4

Answer: A. y = 4

y = 4 keeps y fixed for every x: a horizontal line.

Why the other answers are wrong

B. x = 4
x = 4 is vertical.
C. y = 4x
y = 4x rises with slope 4.
D. y = x + 4
y = x + 4 rises with slope 1.

More Algebra questions

Not affiliated with the College Board. SAT is a trademark of the College Board.