Which of the following is the equation for all straight-line equation?
1) y = 4x2 2) x = 9y2 3) x2 + y2 = 9 4) y = 4x + 9
A straight line equation is a homogenous, single degree equation of two variables.
Answer: Option (4) y = 4x + 9 matches with the above definition, and is the required equation of the line.
Go through the explanation to understand better.
The standard equation of a straight line is y = m x + c
In the given options, y = 4x + 9 is the only equation which of the form y = m x + c.