Understanding The Variables And Coefficients In Algebra

In my previous article, we took an example from the daily life and proved that daily life activity to be algebraic activity. We also established a simple algebraic expression in two variables. In the algebraic expression we defined some terms and two of them were variables and constants. Algebra students must know the difference between a variable and a constant. As you already know that a variable is an unknown quantity which keeps on changing. Variables are represented by letters from the alphabet. I am giving another shot to explain variables further by explaining variables in contrast with fixed quantities or constants. Carefully read the following sentences and figure out the difference between them. Number of minutes in an hour. Number of cars in a mall's parking lot. Number of states in the USA. Amount of commission earned by a sales person. Amount of water to fill 2L can. Notice that, sentence number 1, 3 and 5 give the information which tells about some thing known and certain. Any person can tell number of minutes in an hour, which are always 60. Number of states in the USA is always 50 and same way amount of water in 2L can is fixed all over the world, and everybody can make a reasonable guess of it. Now look at sentence number 2, what do you think about number of cars, a variable or a fixed (constant) number? It is easily understood that the number of cars is not fixed and is different for different times of the day. Therefore no one can tell it for sure that how many cars in the parking lot during any day. So, number of cars in the parking lot of a mall is changing every moment, hence, is a variable (remember a variable is always a number but can take different values at different times). In our example, it can be any number from zero to the maximum capacity of the parking lot. Note that instead saying that unknown number of cars in the parking lot, mathematicians prefer to say "x" number of cars in the parking lot. That's it from me on variables. The other sentence about the commission of a sales person is variable again and you can understand it easily now. I take you further for more practice on variables and constants. Read the following phrases and choose between the variables and constants. Speed of a car in the city. Number of days in a week. Number of legs of a dog. Your weight. Height of a person from 18 year to 50 years of age. Height of a 2 year baby. Number of rooms in your house. Yearly family income. Weight of your necklace. Rainy days in a year.