2.  y-intercept form / slope intercept form  Slope Intercept form y = mx + b  The y-intercept value is immediately seen when the equation is in y intercept form -- making it easy to sketch on a graph.  Specifically, when looking for the y-intercept you set x to zero and solve the equation. In the above the mx falls out.  Similarly, when looking for the x-intercept you set y to zero and solve the equation.

3. Definition – an extraneous solution is one that does not satisfy the original equation.

4.  When multiplying or dividing an equation by a variable quantity, it is possible to introduce an extraneous solution.  Step 1: When variables are in the denominator the objective is to get to first get to a Common Denominator through multiplication.  Step2: Simplify by Combining Like Terms.  Step3: Determine if you have introduced an Extraneous Solution by checking your answer. Note Step 3 is only necessary if you multiplied by a variable as part of step 1.