Legends & Deeds - Every Fact About Lines and Linear Equations in One Song Lyrics

Oh there's lines, forms of lines
All these equations in disguise
Yeah lines, forms of lines
You just can't let them fool your mind
Oh we've got standard form
A x plus b y equals c
Slope intercept form
Y equals m x plus b
Point slope form
Y minus y one equals m times x minus x one
Oh there's lines, lots of lines
You just need two points to form a line
Yeah lines, lots of lines
Or a point and slope is fine
Yeah, we've got horizontal lines
Whose equation is just y equals a number
Vertical lines
Whose equation is just x equals a number
Rising lines have a slope that's positive
Falling lines have a slope that's negative
Parallel lines have exact same slopes
They're also called inconsistent lines
They'll never ever ever ever intersect
The lines with the same slope and y intercept
Are dependent lines, they coincide
Perpendicular lines have negative reciprocal slopes
And cross once in the x y plane
And now that you mention the x y plane
The x axis is a horizontal line
Doesn't have a slope, so y equals zero
The y axis is a vertical line, x equals zero
Slope is undefined
Lines with different slopes only cross one time
Where they intersect is called a solution
To solve a system of linear equations
Use elimination or substitution
If you happen to see an inequality sign
Either draw a dotted or solid line
It depends if there's a line right under the sign
Then shade the region where the solution is defined
The slope of a line is just rise over run
The change in y over change in x
And if you're still perplexed, just study those lines
And that's it folks, see you next time