Question 169955
March 14, 2010

Math 208 Week 4 DQ 2
By looking at two linear equations, how can you tell that the corresponding lines are parallel?
	 The first thing to look at when trying to figure if an equation is going to be parallel we must look at it in slope- intercept form (Y=MX+B), this will allow the determination of parallelism come easily.  So if the value in the M spot is the same and the value of B is different this shows it’s a parallel line. If the equation is given in standard form (AX+BY=C) you will have to look at it as a fraction so A/B reduced to its simplest form for both of the equations. If these lines are different then they are not parallel, if the same they are. While doing this we also have to look at C/B reduced to its simplest form to determine if it is parallelism. 

Examples: 
2X + 4Y = 6
X+ 2Y = 3



A/B for the first equation is 2/4 which reduces to 1/2 
A/B for the second equation is 1/2 

They are the same, so you potentially have parallel lines.

C/B For the first equation is 6/4 which reduces to 3/2
C/B For the second equation is 3/2

they are also the same so the lines are the same line, not parallel lines