Need quick math help!

Discussion in 'Community Discussion' started by twistedlegato, Jan 28, 2007.

  1. twistedlegato macrumors 65816

    twistedlegato

    Joined:
    Jun 15, 2006
    #1
    I know this is probabley very easy for most of you, but let i remind you, i am in pre-algabra, though i am in a gifted class!

    Given the equations, determine the slope of the line.
    Give the y-intercept.

    1) 5x+2y=7


    2)7x+3y=9


    Thanks alot!:)
     
  2. psychofreak Retired

    psychofreak

    Joined:
    May 16, 2006
    Location:
    London
  3. twistedlegato thread starter macrumors 65816

    twistedlegato

    Joined:
    Jun 15, 2006
    #3
    Can you explain?
     
  4. ®îçhå®? macrumors 68000

    ®îçhå®?

    Joined:
    Mar 7, 2006
    #4
    1. Gradient -2.5, y intercept 3.5
    2.Gradient -2 and 1/3, y intercept 3
    Is this correct or am i being really stupid??

    Rats just beaten. Make the integer infront of y=1.
    y= mx + c where m is the gradient and c is the y intercept. Make x=0 and the y intercept is obvious and the gradient is the integer infront of the x. Is this explained well enough??
     
  5. psychofreak Retired

    psychofreak

    Joined:
    May 16, 2006
    Location:
    London
    #5
    There are two ways to find gradient and point of intercept. The easiest for this solution is:

    y=mx + c

    (m being the gradient, and c the y intercept)

    rearrange the equations to y=....
    find the number of x's (this is the gradient, and the other number, the y intercept)

    1. y= -2.5x + 3.5
    2. y= -7/3x + 3
     
  6. psychofreak Retired

    psychofreak

    Joined:
    May 16, 2006
    Location:
    London
    #6
    Too late biznitchwizzle....oh how I've longed to say that...
     
  7. twistedlegato thread starter macrumors 65816

    twistedlegato

    Joined:
    Jun 15, 2006
  8. ®îçhå®? macrumors 68000

    ®îçhå®?

    Joined:
    Mar 7, 2006
    #8
    By doing AS level maths and being taught it ;) (and also being in an express set)
     
  9. bearbo macrumors 68000

    bearbo

    Joined:
    Jul 20, 2006
    #9
    5x + 2y = 7
    =>2y = 7-5x
    =>y = 3.5-2.5x

    3.5 is intercept, -2.5 is slope

    7x + 3y = 9
    =>3y = 9 - 7x
    => y = 3 - 7/3x

    3 is intercept, -7/3 is slope
     
  10. twistedlegato thread starter macrumors 65816

    twistedlegato

    Joined:
    Jun 15, 2006
    #10

    AHHHH!

    I learned to do it with fraction, not decimals so i was cunfused!

    Thanks everyone!
     

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