Why Variables Work

So, you’ve heard of X and Y before, but why do we use them? Algebra can be used in the real life world in many ways, but why do we use X and Y frequently? Why do they work?

The answer is deep in the core of the variable itself, the constant replacing the variable.

Say we have this problem:

2x + 5 = 3y – 4

Variables are replacements for constants in linear and exponential problems.

We can eliminate 4 by adding four to both sides getting:

2x + 9 = 3y

I find multiples of three to replace x:

3, 6, 9, 12, 15…

Putting 3 as x will make the left side 15. I divide 15 by 3 to get 5.

Since this is a linear equation, I can graph the equation to see the how big the answer increases by. Here are some points I can create on a coordinate grid:

(3, 5);  (6, 10);  (9, 15)…

That is how variables work. If you have any ideas for another informational essay or a question on this post, comment below. I will try to answer it.

 

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Why Variables Work

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