In my college experience, I have noticed that many students struggle
through math problems, regardless of their complexity, and several of
my classmates come to me for help. I have seen that they were not
taught to solve math problems, but to find answers. In this tutorial,
I will present a technique to problem solving that will bridge the
gap between finding the answer and solving the problem.
The first step to solving a math problem is to put away your
calculator. Too many people approach a math problem with a calculator
in hand. Set the calculator aside, and grab your pen (or pencil) and
paper. By writing your problem down (i.e. not doing the problem
entirely in your head), you make it much easier to catch simple
mistakes, such as dropping a negative sign, or forgetting an
exponent.
Once you have your pen and paper, write down the original problem. If
it is a word problem, write down all of the given information; this
will let you construct an equation more easily. This tutorial will
assume you already have an equation, as one could write an entire
book on how to analyze a word problem.
A word of warning to you: this next part is where most people make
the most mistakes. If you thought it was strange that I said to grab
your pen, here’s why: if you make a mistake with a pencil, you will
most likely erase it. If you write in pen, you cannot erase it. If
you use a pen, your work is easier to see and it is easier to catch
mistakes. If (when?) you make a mistake, it is not a big deal! Just
cross it out and move on. By merely crossing it out, you can look
back at it and keep yourself from doing the same thing again, or even
catch your mistake later. Be bold! Make your mistakes easy to see,
and make them only once.
Now, on to the hard part. The most basic part of solving a math
problem is isolating like terms. Think of adding apples and oranges.
If you have 3 apples and 1 orange, you can’t say “I have 4
orange-apples,” because you don’t! You have 3 apples and 1
orange. What you want to do in your math problem is move your like
terms together and put them on opposite sides of the “equal”
sign. For example:
12x + 7y = 2xy //Move the y terms together by subtracting12x = 2xy – 7y //the same thing from both sides.
“Wait
a minute,” I hear you saying, “That doesn’t look any better!”
Ah, but wait. You have “something” times y, minus “something”
times y. Now you can factor out the y, leaving you with y times
“something.” In our example, that would be:
12x = 2xy – 7y //Factor out the y term12x = (2x - 7)(y)
Now
we still want only like-terms together, so we undo the times function
that is making the
(2x-7)
stuck to the y. The inverse (or undo) function of “times”
(multiplication) is “divided by” (division), so:
12x = (2x – 7)(y)12x = (2x – 7)(y) //Undo the function of y(2x – 7)
12x = y //Flip so that y is on the left
2x-7
y = 12x //(That's how your professors like it)
2x-7
Ta-Da!
You have solved an equation for y using this foolproof method. The
only type of equation that I wouldn’t use this general method for
is a quadratic (ax2 + bx + c = 0), but you should already
have a formula for that if you’ve had Algebra 1 and/or 2. Now, go
forth, and conquer the world with your amazing mathematical skills!
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