Graphing Equations in Slope-Intercept Form LESSON 4–1 Graphing Equations in Slope-Intercept Form

What is the slope of the line that passes through (–4, 8) and (5, 2)? 5-Minute Check 1

Suppose y varies directly as x and y = –5 when x = 10 Suppose y varies directly as x and y = –5 when x = 10. Which is a direct variation equation that relates x and y? 5-Minute Check 2

Find the next two terms in the arithmetic sequence –7, –4, –1, 2, ….

Is the function represented by the table linear? Explain. 5-Minute Check 4

Mathematical Processes A.1(E), A.1(F) Targeted TEKS A.3(A) Determine the slope of a line given a table of values, a graph, two points on the line, and an equation written in various forms, including y = mx + b, Ax + By = C, and y - y1 = m(x - x1). A.3(C) Graph linear functions on the coordinate plane and identify key features, including x-intercept, y-intercept, zeros, and slope, in mathematical and real-world problems. Also addresses A.2(A). Mathematical Processes A.1(E), A.1(F) TEKS

slope-intercept form constant function Vocabulary

Concept

Write and Graph an Equation Write an equation in slope-intercept form of the line with a slope of and a y-intercept of –1. Then graph the equation. Example 1

Write an equation in slope-intercept form of the line whose slope is 4 and whose y-intercept is 3. Example 1

Changing from standard to Slope intercept.         Example 1

Graph Linear Equations Graph 5x + 4y = 8. Example 2

Graph 3x + 2y = 6. Using Slope-Intercept Form. Example 2

Graph Linear Equations Graph y = –7. Example 3

Graph 5y = 10. Example 3

Write an Equation in Slope-Intercept Form Write the equation in slope-intercept form for the line shown in the graph? Example 4

Write the equation in slope-intercept form for the line shown in the graph? Example 4

Example 4

Write and Graph a Linear Equation HEALTH The ideal maximum heart rate for a 25-year-old exercising to burn fat is 117 beats per minute. For every 5 years older than 25, that ideal rate drops 3 beats per minute. A. Write a linear equation to find the ideal maximum heart rate for anyone over 25 who is exercising to burn fat. B. Graph the equation. C. Find the ideal maximum heart rate for a 55-year-old person exercising to burn fat. Example 5

A. The amount of money spent on Christmas gifts has increased by an average of $150,000 ($0.15 million) per year since 1986. Consumers spent $3 million in 1986. Write a linear equation to find the average amount D spent for any year n since 1986. Example 5

B. The amount of money spent on Christmas gifts has increased by an average of $150,000 ($0.15 million) per year since 1986. Consumers spent $3 million in 1986. Graph the equation. A. B. C. D. Example 5

C. The amount of money spent on Christmas gifts has increased by an average of $150,000 ($0.15 million) per year since 1986. Consumers spent $3 million in 1986. Find the amount spent by consumers in 1999. A. $5 million B. $3 million C. $4.95 million D. $3.5 million Example 5

Graphing Equations in Slope-Intercept Form LESSON 4–1 Graphing Equations in Slope-Intercept Form