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Math Help - Inequalities.

  1. #1
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    Inequalities.

    How would I solve this?

    25 - 6b (Less than and equal to sign) -b - 60

    Any help would be appreciated.
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  2. #2
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    you bring -6b in the other side it becomes 6b and you take -60 in the other side it becomes 60...you will get
    25+60(less or equal than)-b+6b
    85(less or equal than)5b
    17(less or equal than)b which means b(greater or equal than)17
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  3. #3
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    Quote Originally Posted by largebabies View Post
    How would I solve this?

    25 - 6b (Less than and equal to sign) -b - 60

    Any help would be appreciated.
    25 -6b <= -b - 60 ??

    add 25 to 60.

    -6b <= -b -35

    add b to both sides.

    -5b <= - 35

    divide by -5, when dividing by a negative you must flip the inequality.

    answer is

    b \geq 17
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  4. #4
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    25-6b \leq -b -60

    85 \leq 5b

    17 \leq b
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  5. #5
    Super Member 11rdc11's Avatar
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    Quote Originally Posted by p00ndawg View Post
    25 -6b <= -b - 60 ??

    add 25 to 60.

    -6b <= -b -35

    divide by -6, when dividing by a negative you must flip the inequality.

    answer is

    b >= b/6 + 35/6
    Check this agian, there is a mistake.
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  6. #6
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    Quote Originally Posted by 11rdc11 View Post
    Check this agian, there is a mistake.
    caught it.
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  7. #7
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    Thank you all for your help, although now I can't figure out this equation. I've tried it multiple times and end up getting -6 each time when I need -10

    8.25n - 12 (greater than or equal to) 14.25n + 48
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  8. #8
    Super Member 11rdc11's Avatar
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    8.25n -12 \geq 14.25n +48

    -60 \geq 6n

    -10 \geq n
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  9. #9
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    Quote Originally Posted by largebabies View Post
    Thank you all for your help, although now I can't figure out this equation. I've tried it multiple times and end up getting -6 each time when I need -10

    8.25n - 12 (greater than or equal to) 14.25n + 48

     8.25n-12 \geq 14.25n + 48

    add 12.

    8.25n \geq 14.25n + 60

    subtract 14.25 n

     8.25n - 14.25n \geq 60
    divide by -6 and flip sign

     -6n \geq 60

     n \leq -10
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  10. #10
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    it does give -10
    8.25n-12(greater or equal than)14.25n+48
    you 8.25 in the other side it becomes -8.25 and you bring 48 in the other side,it becomes -48..you will get
    -12-48(greater or equal than)14.25n-8.25n....you will get
    -60(greater or equal than)6n.....then you divide -60 by 6..you will get
    -10(greater or equal than)n which means...n(less or equal than)-10
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  11. #11
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    One last question (that I need help on) before I stop spending my life on here :P

    x/3 + 7 > 1/4x (it's 1/4x not 4x) +5

    An explanation on turning fractions into numbers would also help alot too, never been really sure how to do that
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  12. #12
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    no need to turn them into numbers..just join them together
    if you bring x/4 in the other side..it becomes -x/4
    and if you bring 7 on the other side.it becomes -7..you will get
    x/3-x/4(greater than)5-7
    x/12(greater than)-2
    x(greater than)-24
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  13. #13
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    \frac{x}{3} + 7 > \frac{x}{4} + 5<br />

    multiply both sides by 12 to "clear" the fractions ... the result is a "piece of cake" inequality

    4x + 84 > 3x + 60

    x > -24
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  14. #14
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    Alright, I have another one for you guys.

    "An electronics store is advertising 35% off the regular price of any mpeg player in stock"

    "Sheila has $165 to spend on a mpeg player. Write and solve an inequality which expressed the different amounts of money which she can spend on a mpeg player."

    I'm preety terrible at doing written problems, it just doesn't click
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  15. #15
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    Quote Originally Posted by largebabies View Post
    Alright, I have another one for you guys.

    "An electronics store is advertising 35% off the regular price of any mpeg player in stock"

    "Sheila has $165 to spend on a mpeg player. Write and solve an inequality which expressed the different amounts of money which she can spend on a mpeg player."

    I'm preety terrible at doing written problems, it just doesn't click
    Let A be the amount of money that Shiela can spend.

    A\leq 165.

    Let M_{old} be the original price of an MPEG player, and if the New price M_{new} is 35% less, then it is 65% of the original price, or \frac{13}{20} of the original price.

    M_{new}=\frac{13}{20}M_{old}

    and so M_{old} = \frac{20}{13}M_{new}.

    If M_{new} \leq 165 then Shiela can buy it.

    Or if M_{old} \leq \frac{20}{13} \times 165 she can buy it.
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