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I have never understood algabra and probably never will. Please someone help me get these:

1) -9 (2 x2 - 3y)=
2) -7-x- (y+z)=
3) x2 - x + 2x=
4) 2 - x2 +x - 3x=
6) x2 +y2 - x+2x + 3x2 -4y2=


Asked by Anonymous at 10:37 AM on Sep. 17, 2009 in Just for Fun

This question is closed.
Answers (6)
  • Assume you are simplifying:

    1) -9 (2 x2 - 3y)= -18x2 + 27y (multiple the (-9) by each items inside the paranthesis. )
    2) -7-x- (y+z)= -7 -x -y - z (minus (y+z) is really (-1) x (y+z) )
    3) x2 - x + 2x= x2 + x (-1x + 2x --- thus -1+2 = 1 so 1x)
    4) 2 - x2 +x - 3x= 2 - x2 -2x (same as bove 1x - 3 x is 1-3 which is -2 so -2x)
    5)5y-y= 4y
    6) x2 +y2 - x+2x + 3x2 -4y2=
    x2 + 3x2 + y2 -4y2 -x + 2x (combine like items)
    4x2 - 3y2 +x Standard forms is highest expont to losest so I think the correct form would be:
    4x2 + x - 3y2

    Does that help? Basicly you add or multiple the coefficient of the numbers with the same variables.

    I love math :)

    Answer by ferdo0204 at 11:12 AM on Sep. 17, 2009

  • Always hated Algebra, loved Geometry! You need to know what the values are for x and y in the above problems. For the problems with parentheses (1 and 2), you do the math inside the paratheses and work your way out. I work with K-5, and they are starting kids on pre-algebra concepts in first and second grades!

    Answer by emnasmom at 10:44 AM on Sep. 17, 2009

  • is "x2" like... 2 is an exponent?

    so 2 * x2 = x4
    -9 (x4-3y) and distribute the -9
    -9 * x4 + -9 * -3y

    Something like that, not sure though I haven't done algebra for a few years

    Answer by Anonymous at 10:52 AM on Sep. 17, 2009

  • I dunno...i go ask my 3rd grader for ya,k?

    Answer by Anonymous at 11:22 AM on Sep. 17, 2009

  • Wow Anon:22
    Ferdo0204, no offense meant, but are you sure on number 2? It doesn't seem right to me. For that to be the accurate answer, wouldn't there have to be brackets around the -x(y+x)? Like this [-x(y+z)]? To be fair, the last time I had to do complex algebra was years ago. I took trig my junior year in high school, and since then have only done a bit to help my husband through his college math courses which were more basic since they were just gen ed.

    Answer by Mom1Stepmom1 at 11:31 AM on Sep. 17, 2009

  • Don't let Algebra intimidate you. (I know it has that effect on a lot of people). I'm having to help my 6th and 4th grader at home with these concepts.

    Since you don't have a value for the variables (the letters), just assume you have to simplify the problem. (You can't actually "solve" it unless you have a number to plug in for the letters.) That means you need to reduce the problem to as few instances of a variable as possible.

    For example:


    Imagine that before the "y" is a 1. Then just do the math across as if the "y" isn't even there. 5y - 1y would be the same as 5-1. 5-1 = 4. So your answer is 4y.

    The only time you can't do that is when a variable has an exponent. X^2 is not the same as X. In that case, just arrange them from largest exponent to smallest and simplify each one separately.

    2 + 3X - x + 4x^2 would then be 4x^2 + 2x + 2

    Answer by geminilove at 11:45 AM on Sep. 17, 2009