candy 發問於 科學及數學數學 · 1 十年前

文字題 一元一次不等式 幫幫我呀 thx 10分

已知3乘以x加上4小於-11,求x值的可能範圍.

若兩個連續奇數的和不大於80,求當中較小的數的最大可能值.

若兩個連續偶數的和不小於36,求當中較大的數的最小可能值.

已知何先生有$300,他打算購買6張戲和數罐票汽水.若每張戲票和每罐汽水的售價分別是$45和$6,問何先生最多能買多少汽水?

要步驟 thx thx

3 個解答

評分
  • 匿名
    1 十年前
    最愛解答

    plus minus times divided by equals

    1.

    x times 3 plus 4 smaller or equals to 11

    x times3 smaller or equals to -15

    x smaller or equals to -5

    2.

    Suppose the two continuous odd numbers are x and x plus 2.

    x plus (x plus 2) smaller or equals to 80

    x times 2 plus 2 smaller or equals to 80

    x plus 1 smaller or equals to 40

    x smaller or equals to 39

    So the smaller one smaller or equals to 39.

    3.

    Suppose the two continuous even numbers are x minus 2 and x.

    (x minus 2) plus x larger or equals to 36

    x times 2 minus 2 larger or equals to 36

    x minus 1 larger or equals to18

    x larger or equals 19

    But because of x is even numbers ,so x larger or equals 20

    4.

    Suppose a can coca cola's amount is a.

    6 times 45 plus 6a smaller or equals to 300

    270 plus 6a smaller or equals to 300

    6a smaller or equals to 30

    a smaller or equals to 5

    So he can buy 5 can coca cola at most.

    資料來源: 自己
  • shingo
    Lv 6
    1 十年前

    1.

    3x+4<-11

    3x<-11-4

    3x<-15

    x<-5

    ans:x<5

    2.

    兩奇數係x同x+2

    x+x+2<80

    2x+2<80

    2x<78

    因為x<39

    x=37

    ans:37

    3.

    兩偶數係x同x+2

    x+x+2>36

    2x+2>36

    2x>34

    x>17

    x=18

    ans:18

    4.

    300-45x6=30

    30/6=5

    ans:5

  • 1 十年前

    已知3乘以x加上4小於-11,求x值的可能範

    3x+4<-11

    3x+4-4<-11-4

    3x<-15

    x<-5

    可能範圍.x<-5

    若兩個連續奇數的和不大於80,求當中較小的數的最大可能值.

    .(x+1)(x+3)<80

    x^2+x+3x+3<80

    x^2+4x-77<0

    (x+11)(x-7)<0

    x+11<0 or x-7<0

    x<-11(rej) or x<7

    最大可能值x<7

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