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## 6th grade

### Unit 6: Lesson 8

Writing algebraic expressions introduction- Writing basic expressions with variables
- Writing algebraic subtraction expressions
- Writing basic expressions with variables
- Writing basic expressions with variables
- Writing expressions with variables
- Writing expressions with parentheses
- Writing expressions with variables & parentheses
- Writing expressions with variables
- Writing expressions with variables

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# Writing algebraic subtraction expressions

We look at a few examples of how to write algebraic expressions with subtraction in the correct order based on different wordings.. Created by Sal Khan.

## Want to join the conversation?

- this place is amazing. Thank you Khan Academy(7 votes)
- When we swap why can't we have it the other way like when we have x-2 why can't it be 2-x i know it is incorrect already but it is still a question?(3 votes)
- Instead of x-2 why can't we do 2-x?(2 votes)
- 2-x is incorrect.

Why, yes because X is variable. So X can be sometime 2,6,1 or whatever.

So example:

If 2-x x=5

then 2-5 = -3

so this is wrong answer

sorry, I'm not that good at English.(1 vote)

- this is very simple. maybe that why no one has commented?(2 votes)
- I have no questions(2 votes)
- why hasn't people commented?(1 vote)
- No one has had any questions yet....(2 votes)

- this messges is from 20202 dont four get me(1 vote)

## Video transcript

- [Instructor] We have
different statements here that can each be expressed
as an algebraic expression, and as you might have guessed, I would love you to pause this video and try to write each of these statements as an algebraic expression
before we do it together. All right, now let's work on it together. So this first statement,
we have two less than x. So my brain thinks, all
right, let me start with x, and how am I going to
get two less than that? Well, I'm going to subtract two. And this is an interesting example because you see the order that we see it in the sentence is not the order that we would necessarily write it in the expression right over here. Very important to think
about, what is going on here? What is being described? Now, this next statement,
y fewer than three. Well, in my mind, I'm
going to start with three and I'm going to be y fewer than that. So I'm gonna start with three and then I'm going to
be y fewer than that. Now, these first two
statements are similar in that you have something
less than something else or something fewer than something else. They just swapped the
number and the variable. Now, this third statement,
x decreased by five. So my mind is thinking,
what am I starting with? I'm starting with an x and
I'm decreasing it by five. So I can do that as minus five, or I'm gonna take five away from it.