Posts Tagged ‘variables’
Friday, November 20th, 2009
How to Pick Variables
Description
A detailed tutorial on how to pick variables. Step by step tutorial including several examples of how to pick variables for reference.
Overview
Variables are letters picked to represent unknown values in expressions and equations. Usually they are lowercase, but they can be made uppercase. When trying to pick a variable, you must choose wisely. x is the most common variable, followed by n. x is picked because people associate it with the unknown, and n is picked because it stands for “number.” The variable should be easily recognizable – you should not use a variable that looks like another number or some symbol of a mathematical operation. You should check to see what is included in your equation – for instance, m stands for slope, so if you are doing an equation with slope you need to pick a different variable to avoid confusion. And you should always pick a variable that makes sense – the first letter of your subject matter usually works quite well.
Tags: a, algebra, b, c, choose, equation, expression, lowercase, m, mathematical, n!, number, operation, slope, symbol, unknown, uppercase, value, variable, variables, x, y, z
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Thursday, September 17th, 2009
Introduction to Combinations
Description
A detailed tutorial on the solving of combinations. Step by step tutorial including several examples of how to solve combinations for reference.
Overview
Combinations are often used with permutations. A combination is actually just the written representation of the permutation – with the permutation, you figure out how many different combinations there are, but with combinations you actually write down what those combinations are, not just how many there is. Many people prefer permutations because permutations are a lot less work. However, combinations do come up frequently, most notably in logic courses like discrete math.
Tags: combination, combinations, discrete math, items, Math, multiplication, numbers, possibilities, precalculus, sets, statistics, variables
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Thursday, September 17th, 2009
Introduction to Permutations
Description
A detailed tutorial on the solving of permutations. Step by step tutorial including several examples of how to solve permutations for reference.
Overview
A permutation is an ordered sequence of elements, also known as a set. Basically, a permutation is when you have a set amount of possibilities to be one thing (typically a variable), and then you have one less than that number of possibilities for your next variable, etc. Often you can use this to figure out exactly how many possible combinations in a set there are. Permutations are used very often in math, all done slightly different depending on the branch of mathematics, but it is first introduced in precalculus.
Tags: items, Math, multiplication, numbers, permutation, permutations, possibilities, precalculus, sets, statistics, variables
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Friday, September 11th, 2009
How to Solve Systems of Equations by Elimination
Description
A detailed tutorial on how to solve systems of equations by elimination. Step by step tutorial including several examples of how to solve systems of equations by elimination for reference.
Overview
There are two different ways to solve systems of equations – substitution and elimination. We will focus on elimination. Elimination is when you want to add or subtract the equations from each other, and eliminate one of the variables that way. If one of the variables is already opposite (Example: -2x on the first equation and 2x on the second) then all we have to do is solve. It is more common for there to not be an opposite, and then we must create one by using multiplication on both the first and second equation. Once you add or subtract your equations, you should find that one variable has cancelled out, leaving you free to solve for the numerical value of the other one. Once you have this numerical value, plug it in for that variable in any of your original equations to find the value of the other variable.
Tags: algebra, elimination, equations, Math, solve, systems of equations, variables
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Friday, September 11th, 2009
How to Solve Systems of Equations by Substitution
Description
A detailed tutorial on how to solve systems of equations using substitution. Step by step tutorial including several examples of how to solve systems of equations using substitution for reference.
Overview
There are two different ways to solve systems of equations – substitution and elimination. We will focus on substitution. Substitution is when you take one equation in you system of equations,and solve for one of the variables. You then plug the solution in for your variable in the other equation, and solve for the value of the remaining variable. You can then take the number only solution and insert it into your solution for the first variable you solved for. It is very easy to come up with no solution when using the substitution formula, because it relies very heavily on your algebra skills, and even the best mathematicians miss things sometimes. But as long as you pay attention to detail you shouldn’t have any problem using this method of solving for systems of equations.
Tags: algebra, equations, Math, solve, substitution, systems of equations, variables
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Tuesday, September 8th, 2009
How to Simplify Equations by Combining Like Terms
Description
This video provides several real world examples of combining like terms to help us visualize what we are supposed to be doing to simplify equations. Several algebraic sample problems are provided in the video.
Overview
Combining like terms is very simple. It is only done with addition and subtraction. The reason they call it combining like terms is because you only combine terms that are alike. For instance, you could not combine 2x and 2y, even though the number 2 is the same. The important part is the variables, and the variables cannot be combined. You can combine the terms 3x and 5x, because they have the same variable. Another example is with exponential value. You cannot combine the terms 2x and 3x^2 because the exponential values are not the same, which makes the variable not the same. When it is possible to combine like terms, simply add or subtract the numbers, and put that number in front of the variable. Then you have combined like terms. This can be done as many times as you like in a problem provided the variables are the same.
Tags: algebra, combine, combining like terms, like terms, Math, simplify, variables
Posted in Algebra | No Comments »
