小六問題數學~~高手入~20點

字典九五折出售,省了9元,原價是?

畫具減價5%出售,售513元,原價?

書包八折出售,家怡買了一個,省了40元,原價?

媽媽用七五折券買戒指,省250元,原價是?售價是?

西褲減價15%出售,售255元,原價?買一條,省多少元?

thxthxthx!!!!!!!

3 Answers

Rating
  • 9 years ago
    Favorite Answer

    1. Let y be the original price of dictionary.

    y-(y*95%)=9

    y-0.95y=9

    0.05y=9

    y=180

    The original price of the dictionary is $180.

    2. Let x be the original price of painting tools.

    x*(1-5%)=513

    x=513/0.95

    x=540

    The original price of the painting tools is $540.

    3.Let the original price of school bag be d.

    d-(d*80%)=40

    d-0.8d=40

    0.2d=40

    d=200

    The original price of the school bag is $200.

    4.Let p be the original price of ring.

    p-(p*75%)=250

    p-0.75p=250

    0.25p=250

    p=1000

    The original price of the ring is $1000.

    5.Let k be the original price of the tailored pants.

    k*(1-15%)=255

    0.85k=255

    k=300

    The original price of the tailored pants is $300.

    2011-05-31 15:27:03 補充:

    拜托唔好抄襲答案!!!!!!!

    Source(s): myself
  • Anonymous
    9 years ago

    我估小六個陣應該係要用中文列式答掛?._.

    字典的原價是:

    9 ÷ (1 - 95%)

    = 9 ÷ 5%

    = 9 × 100/5

    = 180元

    畫具的原價是:

    513 ÷ (1 - 5%)

    = 513 ÷ 95%

    = 513 × 100/95

    = 540元

    書包的原價是:

    40 ÷ (1 - 80%)

    = 40 ÷ 20%

    = 40 × 100/20

    = 200元

    戒指的原價是:

    250 ÷ (1 - 75%)

    = 250 ÷ 25%

    = 250 × 100/25

    = 1000元

    戒指的售價是:

    250 ÷ (1 - 75%) - 250

    = 250 ÷ 25% - 250

    = 250 × 100/25 - 250

    = 1000 - 250

    = 750元

    西褲的原價是:

    255 ÷ (1 - 15%)

    = 255 ÷ 85%

    = 255 × 100/85

    = 300元

    買一條西褲省了:

    255 ÷ (1 - 15%) - 255

    = 255 ÷ 85% - 255

    = 255 × 100/85 - 255

    = 300 - 255

    = 45元

    哇搞掂 我唸D格式啱一般小學掛

    希望幫到你啦:D

  • 9 years ago

    簡單!不用方程式!

    1.9除(1-95%)=9除5%=180元

    2.513除(1-5%)=513除95%=540元

    3.40除(1-80%)=40除20%=200元

    4.250除(1-75%)=250除25%=1000元

    5.原價:255除(1-15%)=255除85%=300元

    省:300-255=45元

    你不覺得方程式麻煩些嗎?

    2011-06-02 19:28:09 補充:

    rai******你的答案和我的答案十分相似,我先答的,你抄襲我嗎?

    Source(s): 自己
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