SOLUTION: Hello out there,I'm writing for some help with some slope-intercept problems,the first one is,Are the following two graphs in a family?If so/explain why,y=3x-2 and y=-2x+1.The next

Algebra.Com
Question 83198: Hello out there,I'm writing for some help with some slope-intercept problems,the first one is,Are the following two graphs in a family?If so/explain why,y=3x-2 and y=-2x+1.The next one is,Are the following two graphs in a family?If so explain why,y=-2x+3 and y=2x+3.The next one is,Change y=x-3 so that the graph of the new equation has a steeper,negative slope the same y-intercept.And the last one is,Write the point-slope form of the line that passes through (3,-3)and(5,1),thanks for whoever can help.
Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
If you graph you get


If you graph you get


Since neither of these graphs share the same slope or y-intercept, they are not in a family (ie they have nothing in common).
---------------------------------------------------------------------------
If you graph you get



and if you graph you get


You will notice that these two graphs have the same y-intercept, so they belong in a family (since they share the same y-intercept).


--------------------------------------------------------------------------

If you have and you want a steeper, negative slope, simply make the slope a large negative value (for the general slope-intercept equation , m is the slope) . So I could choose -7, and that would make a steep, negative slope. So if I graphed I would get



---------------------------------------------------------------------------

Solved by pluggable solver: Finding the Equation of a Line
First lets find the slope through the points (,) and (,)


Start with the slope formula (note: (,) is the first point (,) and (,) is the second point (,))


Plug in ,,, (these are the coordinates of given points)


Subtract the terms in the numerator to get . Subtract the terms in the denominator to get




Reduce



So the slope is







------------------------------------------------


Now let's use the point-slope formula to find the equation of the line:




------Point-Slope Formula------
where is the slope, and (,) is one of the given points


So lets use the Point-Slope Formula to find the equation of the line


Plug in , , and (these values are given)



Rewrite as



Distribute


Multiply and to get . Now reduce to get

Subtract from both sides to isolate y


Combine like terms and to get

------------------------------------------------------------------------------------------------------------

Answer:



So the equation of the line which goes through the points (,) and (,) is:


The equation is now in form (which is slope-intercept form) where the slope is and the y-intercept is


Notice if we graph the equation and plot the points (,) and (,), we get this: (note: if you need help with graphing, check out this solver)


Graph of through the points (,) and (,)


Notice how the two points lie on the line. This graphically verifies our answer.



RELATED QUESTIONS

Hello out there,I'm writing for some help with some slope-intercept problems,the first... (answered by jim_thompson5910)
Hello out there,I'm writing about some problems that I need help with and thanks to... (answered by stanbon)
Hello out there,I need some help with some problems,the first one is Find the excluded... (answered by jim_thompson5910)
Hello out there,I need some help with some factoring problems,the first one is,Solve by... (answered by praseenakos@yahoo.com)
Hello out there,I need some help with some math problems that I'm having a hard time... (answered by tutor_paul)
Hello out there,I need some help with some problems,The first one is,Find the y-intercept (answered by ankor@dixie-net.com)
hello my name is lisa, how are you? I am having trouble with a couple problems but some i (answered by nerdybill)
Hello out there,I need some help with some tough problems,the first one is,Solve the... (answered by ankor@dixie-net.com)
Hello out there,I need some help with some math problems,the first one... (answered by scianci)