4.1 Coordinates and Scatter Plots, p. 203 4.2 Graphing Linear Equations, p. 210 4.3 Quick Graphs Using Intercepts, p. 218 4.4 The Slope of a Line, p. 226 4.5 Direct Variation, p. 234 4.6 Quick Graphs Using Slope-Intercept Form, p. 241 4.7 Solving Linear Equations Using Graphs, p. 250 4.8 Functions and Relations, p. 256

### solution of an equation

when the variable in a single-variable equation is replaced by a number and the resulting statement is true, p24; in two variables x and y is an ordered pair (x,y) that makes the equation true, p210

### linear equation

the variable is raised to the first power and does not occur in a denominator, inside a square root symbol, or inside absolute value symbols, p133

### scatter plot

one way to analyze the relationships between two quantities is to graph the pairs of data on a coordinate axis, p204

### graph of a linear equation

in x and y is the set of all points (x,y) that are solutions of the equation, p210

### slope

m of a nonvertical line is the number of units the line rises or falls for each unit of horizontal change from left to right, 226

### constant of variation

two variables x and y vary directly if there is a nonzero number k such is true that the number k is the _______ _______, p234

### function notation

in general, the symbol f(x) replaces y and is read as "the value of f at x" or simply as "f of x" which does not mean f times x where f is called _______ ________, p257