INPUT ARTICLE: Article: In some circumstances, your system of linear equations may have infinite solutions. This means that any pair of values that you insert into the two variables will make the two equations correct. This happens when the two equations are really just algebraic variations of the same, single equation.  For example, consider these two equations:  2x+8y=18{\displaystyle 2x+8y=18} x+4y=9{\displaystyle x+4y=9}   If you begin working on this system and try creating a pair of matching coefficients, you will find that by multiplying the second equation by 2 you will create the equation 2x+8y=18{\displaystyle 2x+8y=18}. This is an exact match of the first equation. If you proceed through the steps, you will eventually get the result 0=0{\displaystyle 0=0}. A solution of 0=0 means that you have “infinite” solutions or you can simply say that the two equations are identical. If you consider this system graphically and plot the lines that are represented by the two equations, the “infinite” solution means that the two lines lie exactly one on top of the other. It is really only one line. Occasionally you may have a system in which the two equations, when written in standard form, are nearly identical except that the constant term C is different. Such a system has no solution.  Consider these equations:  4x+2y=6{\displaystyle 4x+2y=6} 2x+y=4{\displaystyle 2x+y=4}   At first glance, these look like very different equations. However, when you begin solving and multiply each term of the second equation by 2 to try to create matching coefficients, you will wind up with the two equations:  4x+2y=6{\displaystyle 4x+2y=6} 4x+2y=8{\displaystyle 4x+2y=8}   This is an impossible situation, since the expression 4x+2y{\displaystyle 4x+2y} cannot equal both 6 and 8 at the same time. If you were to try solving this by subtracting the terms, you would reach the result 0=−2{\displaystyle 0=-2}, which is an incorrect statement. In such a circumstance, your response is that there is no solution to this system. If you consider what this system means graphically, these are two parallel lines. They will never intersect, so there is no single solution to the system. It is possible for a system of linear equations to have more than two variables. You may have 3, 4, or as many variables as the problem dictates. Finding a solution to the system means finding a single value for each variable that makes each equation in the system correct. To find a single, unique solution, you must have as many equations as you have variables. Thus, if you have the variables x,y{\displaystyle x,y} and z{\displaystyle z}, you need three equations. Solving a system of three or more variables can be done using the linear combinations explained here, but that gets very complicated. The preferred method is using matrices, which is too advanced for this article. You may wish to read Use a Graphing Calculator to Solve a System of Equations.

SUMMARY: Recognize identical equations as having infinite solutions. Find systems with no solution. Use a matrix for systems with more than two variables.

In one sentence, describe what the following article is about: A cat who is suffering from arthritis may lick the joint that is causing him pain. This arthritic pain can be controlled by giving your cat painkillers, which should reduce his desire to lick the affected area. Talk to your vet if you think your cat is suffering from arthritic pain. Meloxicam (Metacam) belongs to a family of drugs called NSAIDs (Non-steroidal Anti-inflammatory Drugs). Meloxicam works by inhibiting an enzyme, COX-2, which triggers prostaglandin release, which in turn limits the inflammation that leads to fever and pain. This medication may help reduce your cat’s arthritic pain. Talk to your veterinarian before giving your cat this medication. Meloxicam should only be given to well-hydrated animals. Dehydrated animals may have impaired renal function and the additional decrease in blood supply to the kidney caused by the medication may tip the animal into renal failure.  Likewise, meloxicam must be given with or after food. Do not give your cat meloxicam if he is taking other NSAIDs or steroids of any kind.
Summary: Understand that arthritis can lead to hair loss. Consider giving your cat meloxicam. Do not give your cat meloxicam if he is dehydrated.

INPUT ARTICLE: Article: Even though this measurement is taken across the front of your body, making it easier for you to handle the tape measure yourself, your shoulders and arms should still hang as naturally as possible during this process. As a result, asking someone else to take the measurement for you is advised.  Note that if you are only asked for "shoulder width" and not specifically for "front shoulder width," you should use your measurement for "back shoulder width." Back shoulder width is the standard measurement, while front shoulder width is much less common. Your front shoulder width will usually be close to or the same as your back shoulder width, but there can be slight differences based on age and weight. Certain conditions, like scoliosis and osteoporosis, can yield more dramatic differences. For a front shoulder width measurement, look for a tailored shirt that has a wide neckline or consider wearing a shirt with straps. This measurement deals with the supporting points of your shoulders rather than their truth width. As such, a shirt that illustrates how far these supporting points are is better than a snug shirt with a standard or high neckline. Ask your helper to lay the end of a tape measure flat against one shoulder point. Your helper should then extend the tape measure across the front of your body, following the natural curve of your shoulders, until it reaches the opposite shoulder point. The tape measure will not be horizontal or parallel to the floor. Instead, it must bend subtly along with the natural bend of your shoulders. This is your front shoulder width measurement. Write it down and save it for future reference.  Front shoulder width can technically be used for both men's and women's attire, but it is most commonly used when designing or tailoring women's attire. This measurement is typically used when designing or tailoring necklines. Your front shoulder width is the maximum width a neckline can be without falling off your shoulder. This measurement also makes it easier to space straps on bodices in a way that will prevent them from slipping off your shoulders.

SUMMARY:
Ask for help. Wear the right sort of shirt. Measure across the front of your body. Write down the measurement.