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Science-Related Homework Help Mathematics Topic started by: fireflower on Oct 16, 2012



Title: How can you tell whether an equation is a linear equation?
Post by: fireflower on Oct 16, 2012
Today is the first day of school and my Algebra 2 teacher gave us homework for a review of algebra 1. it has been 2 years since i taken algebra 1 (i took it in 8th grade and geometry in 9th grade). The homework says "state whether each equation is a linear equation." I don't really get it. Can anyone explain and work out one of the problems: y = -3x?


Title: How can you tell whether an equation is a linear equation?
Post by: smokin7acehole on Oct 16, 2012
If the equation has a term which has only 'x'  or any other variable , but not x^2, x^3 r any of that types ... or any other function like sin(x) ..etc, its linear.


Title: How can you tell whether an equation is a linear equation?
Post by: smrj07 on Oct 16, 2012
Usually linear equations have y on one side of the =.  Htis is because when you plug in points for x, you should be able to graph a line with (x,y) points.
Hope it helps!!! Good luck in school this year!!!


Title: How can you tell whether an equation is a linear equation?
Post by: leonna1985 on Oct 16, 2012
y= -3x is linear because graphing it makes a straight line!!

But something like this: y=-3x² Is not linear it makes a parabola! Or y=-3x³ or y=-3x^4 etc...

Something like this: y=3 Is linear just draw a straight line across horizontally...

Also something like this: y=2/x is also not linear I think it makes a half-pipe. Not sure if the variable is the numerator or denominator.

What do you mean by work out problems... I will assume you meant graphing them..

To graph y=-3x Start with the y-intercept which is the point (0, 0) So plot the first point at the origin. Then rise 3 squares (Assuming you have graphing paper) then go to the left one square. Draw a line between the two points and you have a linear relationship!!

Hope this helped!! :]


Title: How can you tell whether an equation is a linear equation?
Post by: dauterjudy938 on Oct 16, 2012
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Title: How can you tell whether an equation is a linear equation?
Post by: LESHA on Oct 16, 2012
hey i did the same thing but my school doesn't start for another 2 weeks :\ but a linear equation is usually y=mx+b m=slope and b=y-intercept and in the problem you stated, there is no b which means its on (0,0) [the origin] and you can start there and use slope which in your case is -3 which for slope is rise over run and that turns into -3/1 then you move down 3 and right 1 and to go in the opposite directiong you would flip the sign and it would turn into 3/-1 then those points you got such as (1,-3) is what your y and x are