Title: Section 2-4: Writing Linear Equations
1Section 2-4 Writing Linear Equations
- We have already seen standard form of an
equation, but this form isnt very useful. - We are going to use slope-int. and point-slope
form to write equations.
2Slope-Intercept Form
- y ______ ____ mx b
- Remember, MOST of the time we will still have
______ in the final equation. - m is the _______
- b is the __________
3Write the equation of the line.
- First (and easiest) b ?
- b
- m ?
- m
- y
4Write the equation of the line.
5Write the equation of the line.
6Give the slope and y-int. of each equation.
- y -4x 3
- m
- b
- y 5 - 1/2x
- m
- b
- 8x y 3/4
- m
- b
- 4x - 2y 10
- m
- b
7Give the slope and y-intercept of each line.
8Given the slope and y-int., write the equation
of the line.
- m 0, b 10
- m 1, b 0
- m 0, b 0
9Given the graph, write the equation of the line.
- To write the equation of a line, we need two
pieces of information ___________
________________ - You should be able to get these from _________.
10Point-Slope Form
- Use this form if you are given _________, or a
__________. (as long as the pt. isnt b) - ____________________
- (x1, y1) is one of the given points.
- Use the points to calculate m.
11Give the equation of the line.
- the line goes through (3, 2) (5, 4).
- m
- choose either point, well use (3, 2). Plug in 3
for ___ 2 for ____. - ____________
12Write the equation.
- y - 2 1(x - 3)
- Simplify.
- ______________
- add two to both sides
- __________
13Give the equation of the line through the points
(4, 3) and (7, -2)
- m
- plug either point.
- y - 3
- y
- y
14Give the equation of the line with x-int. 3 and
y-int 2.
- Because we know the y-int. (b), we only need the
slope. - m
- y