If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

## Get ready for Algebra 1

### Course: Get ready for Algebra 1>Unit 1

Lesson 9: Two-step equations

# Two-step equations intuition

This example demonstrates how we solve an equation expressed such: ax + b = c. It's a little more complicated than previous examples, but you can do it! Created by Sal Khan.

## Want to join the conversation?

• Can zero have a negative sign before it? just wondering
• Yes. -0 = 0. Zero is neither positive nor negative, but you can put a negative sign in front of it, and that will not change the value.
• How Difficult is this kind of math problem?
• So If You get a question as easy as this here is how you do it (even is it looks hard it is still easy to do if you break it down:

you start by adding all the non-variable numbers and subtract that from the total

then you divide what's left by the number of x's or y's or whatever letter the variable is and then you add it all together. (if that is too hard i will show you in an easier way)

5x + 10 = 50
50-10= 40
40/5 = 8
8+8+8+8+8 + 10 = 50
or in other words x = 8
• Can someone help me with negative fractions. They are hard to understand.
• This is a hard topic to understand in my opinion...
• Why do I need to know this-
• you dont
(1 vote)
(1 vote)
• Good for you! But remember, this area is for questions. If you understand something, that's great! Try to answer someone else's questions or simply move on to the next topic.
• I've been watching these videos over & over & I still don't understand I only understand a couple but not the whole thing
• I know right I need help like right now with this stuff
• Is there a reason why your cancelling out the 5 instead of the 3x ?? In my engineering degree i do your method and im wrong 100% of the time, then when it shows the way to do it its always the letters that get cancelled first which results in a totally different answer......
• The properties of equality are very flexible. There is no single approach. If you apply the properties correctly (and you make no math errors), then you will get the right result.

Doing the 3x first is not usually done because you will end up working with fractions (which many people hate to work with) and fractions can require extra work steps (like finding a common denominator to add/subtract).

If you did the 3x first, here's what it would look like:
-- divide entire equation by 3: 3x/3 + 5/3 = 17/3
-- Simplify: x + 5/3 = 17/3
-- Subtract 5/3: x = 17/3 - 5/3
-- Simplify: x = 12/3 = 4
Notice, the answer is still: x=4

If by "cancelling out 3x" first, you mean subtracting 3x, then you are introducing an extra step that is not needed to solve the equation. Your goal is to isolate "x". So, you move items away from the "x", which takes 2 steps as Sal shows in the video. If you subtract 3x from both sides, then you would use 3 steps instead of 2.

Hope this helps.
FYI - You might find it more useful to post an example where you got the wrong result (along with your work steps )so someone can help you find what your are doing incorrectly.
• thats not true because your not real
• What's not true because who's not real
(1 vote)
• Tell me how to solve this equation
4(3x-4)=13x