How can I do this algebra problem?

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in Science & Mathematics

1.) -7 - 4x < 13

2.) -3x - 5 < 16

3.) 2x + 3 < 6x - 1

4.) 6x + 3 < 3 ( x + 2)

5.) 2/3x -8 > - 4

6.) 7 - 5x > 9 - 4x

Comments

  • masterdmasterd

    Just do it as if the < is an '=' sign. So you can add/minus a number to each side of the < as long as you do the opposite to that on the other side. Then solve for x.

    E.g.

    1.) -7 -4x < 13

    = -4x < 13 + 7

    = -4x < 20

    so: -20 < 4x

    Answer: -5 < x

    6.) 7 - 5x > 9 - 4x

    = 7 > 9 - 4x + 5x

    = 7 > 9 + x

    = 7 - 9 > x

    Answer: -2 > x

  • anonymousanonymous

    Well, I don't think I should give you the explicit answers for each one, as you wouldn't learn. However, I'lll give you some simple rules that should make them easy to do by yourself.

    1) When adding or subtracting and equal amount from both sides, you treat the inequality ( < or > ) as an equivalent ( = ) sign.

    2) When multiplying r dividing each side by a negative quantity, the inequality must be flipped.

    Example: I'lll take number 6 and solve it out for you.

    7 - 5x > 9 - 4x

    First, you need to isolate the variable, x, to one sidee of the inequality. Do this by adding 4x to both sides.

    (7 - 5x) + 4x > (9 - 4x) + 4x

    Simplify it...

    7 - x > 9

    Then subtract 7 from both sides to isolate the x

    (7 - x) - 7 > 9 - 7

    Simplify again...

    -x > 2

    Now divide or multiple each sid by -1 to make the x positive.

    **Due to the fact that you are multiplying both sides by a negative number, the inequality must be reversed in direction.

    This yields:

    x < -2

  • seitzguy2seitzguy2

    maybe solve every problem for X then graph and shade properly. The section shaded would be your answer. So the first problem would be x>5 and the second would be x>7 so on and so on.

    If you are trying to solve each one individually then just solve for X:

    - 7- 4x < 13 add 7 to both sides

    -4x < 20 divide by -4

    x > 5 don't forget to flip the sign

  • eleanor-hall_60c033c1e966celeanor-hall_60c033c1e966c

    -4x<20 so x>-5

    -3x<21 so x>-7

    4<4x so x>1

    2/3x>4 so 2x>12 so x>6

    -x>2 so x<-2

  • anonymousanonymous

    -7-4x<13

    -4x<7+13

    -4x<20

    x>-5

    maybe you can use this ( #1) as an example for the rest.

  • anonymousanonymous

    You solve a greater/less than problem by first solving the problem the same way that you would if the greater/less than sign was an equals sign. (I'm assuming you know how to do this.) It is the same, but remember, if you divide by a negative, MUST REVERSE THE SIGN. (as in, a > becomes a < and vice versa). Your answer is then: x > __ or x < __.

  • enfeeblenessenfeebleness

    Just asked questions exactly like this.

    Stop getting us to do your homework by phrasing "Whatever-one-I'm-currently-on" as number 1.

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