All GRE Math Resources
Example Questions
Example Question #101 : Algebra
If the coordinates (3, 14) and (–5, 15) are on the same line, what is the equation of the line?
First solve for the slope of the line, m using y=mx+b
m = (y2 – y1) / (x2 – x1)
= (15 – 14) / (–5 –3)
= (1 )/( –8)
=–1/8
y = –(1/8)x + b
Now, choose one of the coordinates and solve for b:
14 = –(1/8)3 + b
14 = –3/8 + b
b = 14 + (3/8)
b = 14.375
y = –(1/8)x + 14.375
Example Question #2 : Coordinate Geometry
What is the equation of a line that passes through coordinates and ?
Our first step will be to determing the slope of the line that connects the given points.
Our slope will be . Using slope-intercept form, our equation will be . Use one of the give points in this equation to solve for the y-intercept. We will use .
Now that we know the y-intercept, we can plug it back into the slope-intercept formula with the slope that we found earlier.
This is our final answer.
Example Question #61 : Geometry
Which of the following equations does NOT represent a line?
The answer is .
A line can only be represented in the form or , for appropriate constants , , and . A graph must have an equation that can be put into one of these forms to be a line.
represents a parabola, not a line. Lines will never contain an term.
Example Question #143 : Coordinate Geometry
Let y = 3x – 6.
At what point does the line above intersect the following:
They do not intersect
(–5,6)
They intersect at all points
(0,–1)
(–3,–3)
They intersect at all points
If we rearrange the second equation it is the same as the first equation. They are the same line.