Substitution Algebra
Substitution algebra is so named because the appropriate technique of
solution to this type of math problem is to substitute known values into a
formula so as to find an answer.
The process is like making chocolate chip cookies. Follow this:
Step One - When you want to make chocolate chip cookies you first have to
make sure you have all the ingredients, the proper measuring devices, an
appropriate cooking pan and an oven that can produce the required temperature.
Call this the given.
Step Two - Next you need a recipe that will produce chocolate chip cookies.
Call this the formula or equation.
Step Three - All the ingredients are applied to the recipe as instructed.
Order, quantities, measurements, temperature, and time are all followed
precisely.
Step Four - The chocolate chip cookies come out of the oven just right.
Step Five - Grab a hand full of chocolate chip cookies and a glass of cold
milk. Then go to it.
But what would happen if a different recipe for say muffins was used? Well
the result wouldn't be recognizable as chocolate chip cookies. How about the wrong temperature or even wrong time in the oven? Again bad
news.
So you see in order for a result to be correct, the proper ingredients must
be used in a correct recipe with great technique to produce a great chocolate
chip cookies.
Hungry now? Me too! But what does this have to do with substitution algebra,
you ask.
Well, substitution algebra is the same deal. The correct ingredients must be applied to the appropriate formula. The
techniques of combining these aspects must be correct to then obtain the answer. Many
electrical calculations are performed with substitution
algebra. To repeatedly obtain a correct answer there are steps to follow. Here
they are in order:
Step One - Write out all the given information with the appropriate symbol
for that specific quantity.
Step Two - Find a formula which uses the given information to find what you
want to know.
Step Three - Write out the formula substituting the given information for
the symbols in the formula.
Step Four - Do the math to arrive at the answer you seek.
Here's an example. The voltage of an AC resistive
circuit like a heating element equals the current in amps I times the hot (on)
resistance R. So we say E = I R. That's the formula which used what we are given
to find what we want.
Here's the given for a problem. Say the current is 2
amps I=2 amps. And the resistance is 60 ohms R=60 ohms. And we want to find the
volts.
Then E = 2 amps times 60 ohms. This is the
substitution equation.
The solution is 2 x 60 = 120. The volts then is 120
volts in this problem.
Although many formulas have more than three symbols,
the technique of solution is the same.
Neat, eh?
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