AlgebraLab

Algebra I Recipe: Quick Graphs Using Slope-Intercept Form

By G Redden

A. Slope-Intercept Form of a Linear Equation is y = mx + b
  1. "m" represents the slope.
  2. "b" represents the y-intercept.
B. How to Graph Using y = mx + b
  1. Solve the equation for y.
  2. Determine the slope and y-intercept.
  3. Graph the y-intercept.
  4. Use the movements of slope (or rise/run) to graph more points begainning at the y-intercept.
  5. Connect the points with a straight line and arrows on each end.
  6. Label the line with its equation.
1.
8x - 4y = 12
2.
5y + 3x = 8
3.
x - y + 4 = 0
4.
x + 3y - 3 = 0
5.
2x + 3y - 4 = x + 5
C. How to Determine if the Graphs of Two or More Equations are Parallel
  1. Solve each equation for "y".
  2. Determine the slope of each equation.
  3. Equations having the same slope are parallel.
6.
Which of the following lines are parallel?

(a) 7x + 5y = -15
(b) –10y = 14x + 8
(c) 5y = 7x + 5
(d) 3y = (-21/5)x - 3