Smile 發問於 科學及數學數學 · 8 月前

My sister maths problem, how to do, thanks?

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1 個解答

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  • 8 月前
    最愛解答

    (a)

    Distance = Speed × Time

    Jenny walked 5x km to the south, took a break and walked 5y km to the north until 1 p.m.

    Therefore, at 1 p.m. her position is (5x - 5y) km relative to her home.

    (b)

    From 9 a.m. to 1 p.m. there were 4 hours.

    It is given that x = 1.5 and the break lasted for 0.5 hour, so

    y = 4 - 1.5 - 0.5 = 2.

    Using the result of part (a), at 1 p.m. Jenny's position is 5(1.5) - 5(2) = -2.5 km relative to her home. That is, she was 2.5 km to the north of her home.

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