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# Graphing proportional relationships from an equation

Let's graph the equation y = 2.5x. For every increase of 1 in x, y increases by 2.5. We call this the "unit rate" or "slope". The graph shows a proportional relationship because y changes at a constant rate as x changes and because y is 0 when x is 0. Created by Sal Khan.

## Want to join the conversation?

• i still don't understand how to do these :(
• I look in the question bar for help and everyone's as lost as I am.
• Plus all these comments are ancient, no one from my class is active on here apparently. They probably need to get upvoted to be seen so I don't think anyone's reading my comments either.
• dude i dont u n d e r s t a n d, please help
• I don't get any of this. PLZ help!
• im glad he smart cause i aint
• aint what
(1 vote)
• Math makes me cry
• take a break, drink some water, and try again after a few minutes (or maybe even the next day!) Never give up!
• At , how can Y change 12.5?
• At Y doesn't change 12.5 it changes by 5 for every time the x changes by 1
• is math related to science
(1 vote)
• Yes, you will encounter a lot of mathematical equations and calculations in chemistry and physics.

Have a blessed, wonderful day!