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    x^2 + 4x - 5 < 0


    ==> (x-1)(x+5) < 0

    how do you define the values of x as : -5<x<1 (the correct answer)

    do you not say


    x - 1 < 0
    x < 1

    x+5 < 0
    x < -5

    But that's wrong? How do you arrive at the correct answer after factorising
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    Name:  Snapchat-5352329081262331777.jpg
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Size:  443.2 KBx^2 + 4x - 5 < 0


    ==> (x-1)(x+5) < 0
    hi there . basically after you've found out your x values . you then draw the graph in with the x values. you first think of the inequality as an equality.
    as y=0 x will be 1 and also -5.
    so then u draw in the graph and after that as it is y<0 you look at the y axis below not above , after that as this is a positive quadratic equation its a smiley face shape meaning it will be between -5 and one and also as it forms a semi circle type shape its within the range so
    therefore x>-5 and x<1
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    (Original post by Feynboy)
    x^2 + 4x - 5 < 0


    ==> (x-1)(x+5) < 0

    how do you define the values of x as : -5<x<1 (the correct answer)

    do you not say


    x - 1 < 0
    x < 1

    x+5 < 0
    x < -5

    But that's wrong? How do you arrive at the correct answer after factorising
    well when x = 1
    (1-1)(1-5) = (0)(4) = 0
    &
    when x = -5
    (-5-1)(-5+5) = (-6)(0) = 0

    the < 0 is showing y<0
    so you know from that info that when y<0
    x is between -5 & 1

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    (Original post by Feynboy)
    x^2 + 4x - 5 < 0


    ==> (x-1)(x+5) < 0

    how do you define the values of x as : -5<x<1 (the correct answer)

    do you not say


    x - 1 < 0
    x < 1

    x+5 < 0
    x < -5
    Surely if both (x-1) and (x+5) are both negative then the product must be greater than zero, ie (x-1)(x+5)&gt;0 which is a contradiction.

    So sketch a graph, put your roots down, and determine from there by looking for what x values the graph is less than 0.
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    Community Assistant
    (Original post by hashir7890)
    ...
    First time I see snapchat being used as means of graph sketching...
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    (Original post by RDKGames)
    First time I see snapchat being used as means of graph sketching...
    lol
 
 
 
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