Warm-Up

Homework Check

Unit 4 Linear FunctionsSlope and introduction to slope-intercept

An equation whose graph is a line is a Linear Equation.

Examples of Linear Equations:

The y-intercept is the y-coordinate of the point where a line crosses the y-axis.

Y-intercept:

SLOPE: (rate of change)

Step 1: Write the slope-intercept form equationStep 2: Substitute the given slope or find it

given two pointsStep 3: Substitute the y-intercept from

Ex) Write an equation of the line with

Write the equation of a line that goes through the points (-3, 2) and (-6, 5) with a y-intercept of 7.

Write the equation of a line that goes through points (1,5) and (3, 9)

Step 1: Find two points on the graph.

Step 2: Find the slope of those points

Step 3: Determine the y-intercept

Step 4: Write the equation of the line

Write an equation of the line:

Write the equation of the line:

Graphing a line given the equation

Step 1: Graph the y-intercept.Step 2: Using the slope, graph a second point

on the line.Step 3: Draw a line through the two points

The base pay of a water-delivery person is $210 per week. He also earns 20% commission on any sale he makes. The equation t=210 + 0.2s relates total earnings t to sales s. Graph the equation.

Homework