➕ Algebra 1 · Linear Functions
Graphing Linear Equations cheat sheet
Everything you need on one page. Print it, or switch on test-yourself mode to blur the answers and check your memory.
Three ways to find points
- Table: pick x-values, work out y
- Slope-intercept: plot (0, b), then rise and run
- Intercepts: y = 0 gives the x-intercept, x = 0 gives the y-intercept
Special lines
- y = b: horizontal, slope 0 (HOY)
- x = a: vertical, slope undefined (VUX)
- A line through the origin crosses both axes at (0, 0)
Is the point on the line?
- Substitute x and y into the equation
- Both sides equal: it is on the line
- Put parentheses around negative numbers
Example
- 3x + 5y = 15
- y = 0 gives (5, 0) and x = 0 gives (0, 3)
- Check (−5, 6): −15 + 30 = 15
Watch out
- (x, y): x comes first
- A negative slope goes down to the right
- Plot a third point to check
Formulas
- Slope-intercept form: y = mx + b: slope m, y-intercept b (the point (0, b))
- y-intercept: Set x = 0 and solve for y
- x-intercept: Set y = 0 and solve for x
- Horizontal line: y = b, slope 0
- Vertical line: x = a, slope undefined
Graphing Linear Equations cheat sheet from HighSchoolQ.com, for personal study use.