McGraw-Hill Education GRE 2019

The x-coordinate designates the horizontal position of a point. If a point is to

the right of the origin, then its x-coordinate is positive. If a point is to the left of

the origin, then its x-coordinate is negative. If a point is on the y-axis, then its

x-coordinate is zero.

The y-coordinate designates the vertical position of a point. If a point is above

the origin, then its y-coordinate is positive. If a point is below the origin, then its

y-coordinate is negative. If a point is on the x-axis, then its y-coordinate is zero.

y

x

(6, –4)

(4, 3)

(2, 0)

(0, 4)

(–3, –3)

(–6, 1)

Properties of a Line

On the coordinate plane, a line is formed by joining two points. Any line on the

coordinate plane will be defined by the following equation:

y = mx + b

x and y can refer to any point on the line, but m and b are constants—they define

properties of a line.

Slope

In the equation y = mx + b, m refers to the slope of the line. The slope of a line

indicates its steepness and whether it is rising or falling.

y

x

Positive slope/steeper

CHAPTER 13 ■ GEOMETRY 431

04-GRE-Test-2018_313-462.indd 431 12/05/17 12:06 pm