A line can be described algebraically using the slope intercept form, The slope intercept form is written: y=mx + b
m= slope
b= y intercept
An example question may look like this.
Put the following in slope intercept form
Put the following in slope intercept form
Find the x-intercept and y intercept for the following line.
-x + 2y =10
Step 1 In order to find the x intercept plug 0 in for y -x+2(0) =10
Step 2 -x+0=10
Step 3 -x = 10
Step 4 x=-10
In order to find the y intercept plug 0 in for x
Step 1. 0-2y =10
Step 2. 0 +2y =10
Step 3. y =5
Point Slope Form
The Point Slope Form is used when a point on the line ( x1,y1) is given or known and the slope, m
m= slope
Write the equation of a line with a slope of 1/2 containing the points (6,-4)?
Horizontal Line Form:
y = 2 ( This number is a constant and is where the line crosses the y axis)
The slope of a horizontal line is zero. They have horizontal change but the vertical change is zero. The rise/run formula for slope always yields zero since rise = 0.
y = mx + b
y = 0x + 2
y = 2
Vertical Line Form:
x = -2 (or any number)
Lines that are vertical have no slope.
They have "rise", but no "run". The rise/run formula for slope always has a zero denominator and is undefined.
What is a linear equation?
Slope of a Line
Step 1. Subtract -3x from each side
Step 2 -2y= -3x +8 Isolate y by dividing by 2
Step 3. y = -3x/-2 + 8/-2 simplify 8/-2 = -4
Step 4 y = 3/2x -4
Step 1. Subtract 7x from each side
Step 2 9y= 7x+27 Isolate y by dividing 9
Step 3. y = 7x/9 + 27/9 simplify 27/9 =3
Step 4 y = 7/9x +3