Slope formula (equation for slope) | Algebra (article) | Khan Academy (2024)

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• Jack Smith

  7 years agoPosted 7 years ago. Direct link to Jack Smith's post “Why is the slope formula ...”

  Why is the slope formula y/x? Why not y-x or y+x?

  Thanks to anyone who answers.
  Jack.

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  (26 votes)

  • Sanjana Gurram

    7 years agoPosted 7 years ago. Direct link to Sanjana Gurram's post “Slope is something that i...”

    

    

    

    Slope is something that is also referred to as the rate of change. For example, if you had a savings account that you deposited no money into initially but you deposit 20$ weekly, your rate of change, or slope for this problem would be 20. This is because your x-value in this situation would be the number of weeks passed since you have created your bank account, and the y-value is how much money you have deposited into your account, fully. Since you are looking at the rate of change between the weeks, you divide the change in y per week, 20, by 1 for the number of weeks. I hope this somewhat answers your question.

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    (69 votes)
• UAO

  4 years agoPosted 4 years ago. Direct link to UAO's post “*Something To Think About...”

  Something To Think About
  I think that when x_2 = x_1 then the slope will become undefined because x_2 - x_1 equals zero. Therefore when you divide y_2 - y_1 it won't be possible.

  Example

  (5,10) (5,15)

  x_1 = 5
  x_2 = 5
  y_1 =10
  y_2 =15

  5 - 5= 0

  15-10=5

  5/0= Undefined

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  (39 votes)

  • Ian Pulizzotto

    4 years agoPosted 4 years ago. Direct link to Ian Pulizzotto's post “Yes, you are correct. Th...”

    

    See Also

    Zero Slope - How To Calculate Zero Slope?, Examples, FAQsWhat Does Zero Slope Mean? How To Calculate Zero Slope - The Story of Mathematics - A History of Mathematical Thought from Ancient Times to the Modern Day6.5: Understanding the Slope of a LineZero Slope Line: Equation And Examples - Science Trends

    Yes, you are correct. The slope of any line through two different points with the same x-coordinate (that is, a vertical line) is always undefined, for the reason you stated.

    Comment on Ian Pulizzotto's post “Yes, you are correct. Th...”

    (16 votes)
• Suzuki

  9 months agoPosted 9 months ago. Direct link to Suzuki's post “why do i have a feeling t...”

  why do i have a feeling that im going to die after i make it through slopes

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  (25 votes)

  • 44386

    8 months agoPosted 8 months ago. Direct link to 44386's post “Because we all will die”

    

    Because we all will die

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    (15 votes)
• Adrian Ambrosetti

  5 years agoPosted 5 years ago. Direct link to Adrian Ambrosetti's post “I think that when X2 = X1...”

  I think that when X2 = X1, the slope is undefined

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  (19 votes)

  • Isha

    3 years agoPosted 3 years ago. Direct link to Isha's post “Yes! That is correct.”

    Yes! That is correct.

    Comment on Isha's post “Yes! That is correct.”

    (4 votes)
• Isaiah softhal

  4 years agoPosted 4 years ago. Direct link to Isaiah softhal's post “bro im honestly so gone”

  bro im honestly so gone

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  (8 votes)

  See Also

  Slope review | Algebra (article) | Khan Academy

  • T̷h̷e̷C̷o̷d̷i̷n̷g̷L̷e̷g̷e̷n̷d̷ INACTIVE

    4 years agoPosted 4 years ago. Direct link to T̷h̷e̷C̷o̷d̷i̷n̷g̷L̷e̷g̷e̷n̷d̷ INACTIVE's post “Slope is basically the ch...”

    Slope is basically the change in the y direction divided by the change in the x direction. If you don't know graphs, you might want to learn that first.

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    (0 votes)
• christian31994

  7 years agoPosted 7 years ago. Direct link to christian31994's post “If I Get The Right Answer...”

  If I Get The Right Answer Then Why Do I Have To Simplify?

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  (3 votes)

  • Isha

    3 years agoPosted 3 years ago. Direct link to Isha's post “Simplifying just makes it...”

    Simplifying just makes it easier to read/understand. It makes it more "simple." Although both are equal, it is just easier to work with if it's simplified afterwards.

    Comment on Isha's post “Simplifying just makes it...”

    (5 votes)
• ✐⭑Sarcastic_Muffin⭑✐

  4 months agoPosted 4 months ago. Direct link to ✐⭑Sarcastic_Muffin⭑✐'s post “How do you know which x a...”

  How do you know which x and y values to plug in? Could you just do random numbers?

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  (4 votes)

  • joshua

    3 months agoPosted 3 months ago. Direct link to joshua's post “If you mean how to find x...”

    If you mean how to find x and y, the problem statement should have provided you with 2 or more points. Since a straight line can be uniquely defined with 2 points, using those 2 points you can find the slope.

    However, if you are asking which point is y₁ and which is y₂, it doesn't matter. Just note that if you have used P₁ for y₁, then you will need to use P₁ for x₁.

    Let's prove that no matter which order you put in, the result is the same, i.e.

    (y₁ - y₂) / (x₁ - x₂) = (y₂ - y₁) / (x₂ - x₁)

    L.H.S. = (y₁ - y₂) / (x₁ - x₂)
    = (-1) * (y₂ - y₁) / [(-1) * (x₂ - x₁)]
    = [(-1) / (-1)] * (y₂ - y₁) / (x₂ - x₁)
    = (y₂ - y₁) / (x₂ - x₁)
    = R.H.S.

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    (4 votes)
• jvald37

  7 years agoPosted 7 years ago. Direct link to jvald37's post “Why do we always take cha...”

  Why do we always take change in y over change in x Why not vice versa ?

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  (5 votes)

  • nisha.scullino

    4 years agoPosted 4 years ago. Direct link to nisha.scullino's post “slope is rise over run, a...”

    slope is rise over run, and rise is y, while x is run.

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    (2 votes)
• Sean Chai

  2 years agoPosted 2 years ago. Direct link to Sean Chai's post “Something to Think About:...”

  Something to Think About:
  When x1 = x2, it means that x1-x2=0. So therefore the formula will simplify to y/0. And as x/0 is undefined, the slope should also be undefined.

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  (5 votes)
• Joy Young

  7 years agoPosted 7 years ago. Direct link to Joy Young's post “in the formula mx+b=y, I ...”

  in the formula mx+b=y, I understand that "m" is the slope and "b" is the y-intercept, but what is x and y?

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  (3 votes)

  • Alan Wang

    7 years agoPosted 7 years ago. Direct link to Alan Wang's post “when you graph the line, ...”

    when you graph the line, mx+b=y and fill in the slope and y-intercept, the x and y represent points that are on the line that you graphed. For example, if the equation was 5x+10=y, you could create pairs of (x,y) coordinates by plugging in numbers for x and y. In this case, if x was 5, y would be 35 or vice versa. Based on this, you could say that (5,35) is a point on the line, 5x+10=y.

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    (5 votes)