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Old 07-27-2007   #1
shooblus
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Default OUCH!!!Algebra...I need help with linear equations, slopes,how do I find the slopes

of the line that contains? the following 2 points of these problems? (2,4);(-1,-4) & (-4,1);(1,2) & (-3,2);(5,-3) & (4,-6),(4,2); & (2,-5);(4-8) & (2,-6);(3,-6)?PLEASE...I appreciate any help at all! Are there any easy answers for this 40 yr. old sruggling with college algebra?
 
Old 07-27-2007   #2
1111
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Your question is confusing, do you want the slope between the two points? if so, use the following equation:M = Slope of the LineM=(Y1-Y2)/(X1-X2)that equation should give you the slope of any linear graph using 2 points in that graph.After you have found the slope, use this equation:Y= mx + bY= Y-valuex= x-valueb = y-interceptEX: i'm going to do one example for the pairs you have given me2,4)-1,-4)M= (4 + 4) / (2 + 1)M= 8/3Next:Y=(8/3)x + bnow, plug in the x and y value4= (8/3)(2) + b and solve for b4= (16/3) + bb= 4 - (16/3)b= -1.333333...so the equation for the first pair is y=(8/3)x-(4/3)I know it looks complicated, but once you've learned the basic concept then everything will be easy.I hope that helps
 
Old 07-27-2007   #3
beautifulgrrl2004
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To find the slope, simply divide [Y2(the 2nd y-value) minus Y1(the 1st y-value] by [X2(the 2nd x-value) minus X1(the 1st x-value)]. This finds the slope of a line with given coordinate points. i.e. (-2, 4) & (4, 8) (X1,Y1) (X2,Y2)---------> see how they correspond?! If you need anymore help, just contact me!
 
Old 07-27-2007   #4
Wingnut19
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The best way to find the slope is "rise over run". Plot the two points on a graph, and you'll get a diagonal line. Start at the lower point, and count STRAIGHT up to the horizontal grid line where the top point is located. This number of spaces is the "rise"Now, count the number of spaces it takes to get to the top point. (left or right) This is the "run". If you have moved to the left, the "run" number should be negative, but if you moved to the right, the "run" should be positive.Then, put the "rise" over the "run", as a fraction. This is the slope, a.k.a. the "m" in y=mx+b. Hope this helps. It would be easier if I could show you on paper.
 
Old 07-27-2007   #5
alyagon
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a linear function is of the type y=a+b*x where a and b are constants and x and y are variables.if the function passes through points (2,4) and (-1,-4) one can substitue x with 2 and y with 4 to get an equation with two unknowns a and bnow we can substitute (x,y) with (-1,-4) to get a second equation with two unknowns a and bnow we have two equations with two unknowns a and bsolve this pair and you will get the equation of the first linethe slope is b.Similarly solve the coeficients of the other linesanother simpler approach would be b=(y2-y1)/(x2-x1) so in the first pair (x1,y1)=(2,4) the second pair (x2,y2) would be (-1,-4)b=(-4-4)/(-1-2)=(-8)/(-3)=(2+2/3)
 
Old 07-27-2007   #6
Jess F
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Slope is fairly easy once you get a hang of it. Here’s how my teacher taught us to calculate it:1.Take a sheet of paper.2. Write your two coordinate pairs one-on-top of the other.3. Label the second number in your second coordinate pair y2. This just means that that is the second y you have on your sheet of paper. Repeat this process for the y above the one you just labeled. Label this y y1 to represent the order in which it was put on your paper.4. Repeat this for the x values.5. In a red marker or different colored pen, arrange the values so that the y values were on top. Do this for the x values but in a different colored pen or marker so that the values are easily identified.6. Beside your block of labled coordinate pairs, Take your red y values and rearrange them (if they aren’t already) so that the second y value is first and the y1 is second. Skip a line and do the same for the x values, being sure x2 is first and x1 is second. Be sure to leave a space in between both y2 and y1 and x2 and x1 values.7. In the space left between the marked y2, y1, x2, x1 values, place a fraction bar.8. To complete this equation, place a minus sign in between y2 and y1. Repute the process for the x values.Congratulations, you have now successfully completed the most difficult part of finding the slope of a line! To finish the problem, just subtract. Don’t remove the fraction bar. Slope is supposed to be in the form of a fraction – rise over run.
 
 

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