writing linear equations...write an equation in slopeintercept form that has a slope of and passes...
TRANSCRIPT
WritingLinearEquations
Section 24
SlopeIntercept Form of a Linear Equation
y = mx + bslope yintercept
m is the slope and b is the yintercept.
Let's graph one as a quick review.
10 8 6 4 2 0 2 4 6 8 10
10987654321
12345678910
x
yGraph the line with equation
.
Example 1Write an equation in slopeintercept form that has a slope of and passes through (4, 1).
You try!Write an equation in slopeintercept form that has a slope of and passes through (4, 3).
PointSlope Form of a Linear Equation
slope
m is the slope and is any point on the line.
coordinates of any point on the line
Example 2Write an equation in pointslope form that passes through the points (3, 8) and (10, 2).
You do one!Write an equation in pointslope form that passes through the points (7, 1) and (3, 0).
Example 3As a salesperson, Sarah Ruth is paid a daily salary plus commission.When her sales are $1000, she makes $100. When her sales are $1400,she makes $120. Write a linear equation to model this situation.
Example 3 continuedWhat does the yintercept represent in the context of this problem?
.
What does the slope represent in the context of this problem?
Example 3 continuedHow much would she make in a day if Ms. Ruth's sales were $2000?
.
Example 4Write an equation for the line that passes through (4, 3) and isperpendicular to the line whose equation is .
You try one!Write an equation for the line that passes through (9, 1) and isparallel to the line whose equation is .