Slope Intercept Form l Slope Intercept form y

Slope Intercept Form l Slope Intercept form: y = mx + b l Where m is the slope l b is the y-intercept

Write an equation of the line whose slope is and whose y-intercept is – 6. Slope-intercept form Replace m with Answer: and b with – 6.

Write an equation of the line shown in the graph. Step 1 You know the coordinates of two points on the line. Find the slope. Let

Simplify. The slope is 2. Step 2 The line crosses the y-axis at (0, – 3). So, the y-intercept is – 3. Step 3 Finally, write the equation. Slope-intercept form Replace m with 2 and b with – 3. Answer: The equation of the line is

Write an equation of the line whose slope is 4 and whose y-intercept is 3. Write an equation of the line shown in the graph.

Graph Step 1 The y-intercept is – 7. So graph (0, – 7). Step 2 The slope is 0. 5 y = 0. 5 x – 7 or From (0, – 7), move up 1 unit and right 2 units. Draw a dot. Step 3 Draw a line connecting the points.

Graph Step 1 Solve for y to find the slope-intercept form. Original equation Subtract 5 x from each side. Simplify. Divide each side by 4.

Divide each term in the numerator by 4. Answer: Step 2 The y-intercept of is 2. So graph (0, 2).

Step 3 The slope is From (0, 2), move down 5 units and right 4 units. Draw a dot. Step 4 Draw a line connecting the points. 5 x + 4 y = 8

Graph

Health The ideal maximum heart rate for a 25 -yearold who is exercising to burn fat is 117 beats per minute. For every 5 years older than 25, that ideal rate drops 3 beats per minute. Write a linear equation to find the ideal maximum heart rate for anyone over 25 who is exercising to burn fat. Words The rate drops 3 beats per minute every 5 years, so the rate of change is beats per minute each year. The ideal maximum heart rate for a 25 -year-old is 117 beats per minute.

Variables Let R = the ideal heart rate. Let a = years older than 25. Equation Ideal rate equals R Answer: rate of change ideal rate years older for 25 times than 25 plus year-old. a 117

Graph the equation. The graph passes through (0, 117) with a slope of Answer:

Find the ideal maximum heart rate for a person exercising to burn fat who is 55 years old. The age 55 is 30 years older than 25. So, Ideal heart rate equation Replace a with 30. Simplify. Answer: The ideal heart rate for a 55 -yearold person is 99 beats per minute.

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. a. Write a linear equation to find the average amount spent for any year since 1986. Answer: where D is the amount of money spent in millions of dollars, and n is the number of years since 1986

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. b. Graph the equation. Answer:

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. c. Find the amount spent by consumers in 1999. Answer: $4. 95 million