- Slope-intercept equation from graph
- Writing slope-intercept equations
- Slope-intercept equation from graph
- Slope-intercept equation from slope & point
- Slope-intercept equation from two points
- Slope
- Slope-intercept equation from graph
- Writing slope-intercept equations
- Slope-intercept equation from graph
- Slope-intercept equation from slope & point
- Slope-intercept equation from two points
- Slope-intercept from two points
- Slope-intercept form problems
- Slope-intercept form from a table
- Slope-intercept form review
Slope-intercept form problems
Learn how to solve problems involving writing an equation in slope-intercept form. Created by Sal Khan.
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- Isn't double minus sign incorrect? Shouldn't be there parentheses? Like 5 - (-2) instead of 5 - -2(18 votes)
- Yes, there should be parentheses separating the minus signs.(14 votes)
- How do I write the slope-intercept form of the equation of the line through: (3,-2), if the slope is undefined?(6 votes)
If a slope is undefined, it means that the x value does not change. Remember that slope is calculated as the change in the y value divided by the change in the x value. If x does not change, then we are dividing by zero, which is undefined. Therefore, an undefined slope is a vertical line through the point you were given.
You cannot really write it in a correct slope/intercept form. Usually this is written as:
x=whatever the x value of your point is.
In your case, the equation would be
And the graph would be a vertical line running through the 3 on the x axis.
Hope that helps :-)(18 votes)
- At8:20, when you had 0=5/6(-3)+b, why did you divide by 3 instead of multiply? And why only the 3 and 6 and not the 5?(5 votes)
- To multply 5/6 (-3):
Change -3 into a fraction: 5/6 (-3/1)
You now have 2 choices:
Option 1) You can multiply the 2 fractions. Multiplying fractions means you multiply numerator * numerator and denominator * denominator. Then reduce.
5/6 (-3/1) = -15/6 = -5/2
Option 2) You can reduce 1st. Reducing cancels out a common factor from the numerator to the denominator. As long as fractions are being multiplied, you can cancel across fractions. This is what Sal did. Sal cancelled out a factor of 3 from -1 and 6.
5/6 (-3/1) = 5/2 (-1/1) = -5/2
Hope this helps.
You may want to review multiplying and reducing fractions.(10 votes)
- 7:300= 5/3(-3) + b why did sal divide -3 by -3 to get a +ve 1?(5 votes)
- Sal did not divide -3 by -3. They were dividing the 0-5.(2 votes)
- mane dis to complicated ion know how to do dis(4 votes)
- Fr I don't understand :/(4 votes)
- Hi, I didn't understand why f(x) and the change in y are equal in the slope equation at14:28. I think they're equal since
f(x)/change in x = change in y/ change in x
Help please(4 votes)
- The function is the product difference from x to y. When you multiply the x by the function, according to that specific problem, you get y. Don't worry, if you're still in grammar/elementary school, you don't have to know this.(4 votes)
- how do you figure out what the slope intercept is?(4 votes)
- First, find the slope. y1 - y2/x1 - x2
Next, plug the slope and one of the coordinates into this equation: y = (slope)x + (y-intercept)
Afterwards, solve the algebraic equation.
Last, write out the equation.
y = (slope)x + (y-intercept)(3 votes)
- I didn't understand the equation f(1.5)=-3,f(-1)=2?(3 votes)
- This is because our function here is
So each time we put in a value of
xwe multiply it by -2
- i dont understand the slope intercept(4 votes)
- watch some videos from before(3 votes)
- 2:57to3:51. In order to find the slope, Sal does (6-0)/(2-5) when in the last video, he said to subtract the first point from the second point. Here, he is doing the opposite. Is this OK? My algebra teacher says that's incorrect and we have to subtract the first point from the second point.(3 votes)
- It does not matter which one is the first and which one is the second as long as you stay consistent in labeling and applying.
So with two points (2,6) and (5,0) you could do (0 - 6)/(5 - 2) and get -6/3 = -2
The other way is (6 - 0)/(2 - 5) and get 6/-3 which is also equal to -2.(4 votes)
In this video I'm going to do a bunch of examples of finding the equations of lines in slope-intercept form. Just as a bit of a review, that means equations of lines in the form of y is equal to mx plus b where m is the slope and b is the y-intercept. So let's just do a bunch of these problems. So here they tell us that a line has a slope of negative 5, so m is equal to negative 5. And it has a y-intercept of 6. So b is equal to 6. So this is pretty straightforward. The equation of this line is y is equal to negative 5x plus 6. That wasn't too bad. Let's do this next one over here. The line has a slope of negative 1 and contains the point 4/5 comma 0. So they're telling us the slope, slope of negative 1. So we know that m is equal to negative 1, but we're not 100% sure about where the y-intercept is just yet. So we know that th