###### Alissa Fong

MA, Stanford University
Teaching in the San Francisco Bay Area

Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts

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# Applications of Linear Equations - Concept

Alissa Fong
###### Alissa Fong

MA, Stanford University
Teaching in the San Francisco Bay Area

Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts

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We often see math applied to the real world through word problems, and the applications of linear equations are seen throughout all our math courses after Algebra. To understand applications of linear equations we need to have an understanding of slope, how to interpret a graph, and how to write an equation. In upper-level Algebra, we apply systems of linear equations to these problems as well.

I'm a math teacher.
And one of the things students ask me all
the time is when are we going to use
this in the real world?
And a lot of the times, you guys, you
really do use math in the real world.
And one of the situations you're going to
see those kind of situations in your
math class is using graphs that describe
linear equations or word problems.

When you're looking at a word problem or
a graph that describes a word problem,
there's a bunch of things
to keep in mind.
One thing to be really sure you're aware
of is the scale on the X and the Y
axis.
By scale, that means how much
are you counting by?
Are you counting by 5s
or counting by 500s.
That's something that's really important
in terms of the real world context.

Along those same lines, pay
attention to the units.
Units meaning are you looking at how much
you're paying in dollars or pounds
or yen or cents or
whatever it is.
All those kinds of units are really important
to keep in mind especially when
you get to the slope.

One of the most common graphs of word
problems is about slopes of distances
and times, because the slope
is distance per time. It's the rate.
It's how fast you're traveling.
So a lot of times you're going to be asked
to interpret the slope of a word
problem graph.

Another thing I want you guys to keep in
mind is the intercepts and what the
intercepts mean on a graph.
Keep in mind that the X intercept means
the Y quantity is equal to
0 .Y intercept means X quantity is equal to 0.

When you're looking at graphs all of these
things are really important to keep in