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Math Help - Need help on 2 problems, a word and linear equation PLease help

  1. #1
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    Need help on 2 problems, a word and linear equation PLease help

    1. 18x+5=3(6x-2) what does x equal?

    2. A ship leaves the harbor moving at 24 mi/h. 3 hours later a second ship leaves from the same harbor at 32 mi/h in the same direction. How long will it take the second ship to overtake the first?
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  2. #2
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    18x+5=3(6x-2)

    Expand him out

    18x+5=18x-6

    Hmmm, two linear functions with the same gradient and different y-intercept. Looks like trouble. I would say there are no solutions to this guy, but why?
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  3. #3
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    thanks what about the second one?
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  4. #4
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    What do you think about the second one?

    Here's a table I drew to figure it out

    <br />
\begin{array}{|c|c|c|}<br />
\text{} & \text{SHIP 1} & \text{SHIP 2}\\ \hline<br />
\text{Start} & 0 & 0\\ \text{After 1 hour} & 24 & 0  \\ \text{After 2 hours} & 48 & 0 <br />
\\ \text{After 3 hours} & 72 & 0  \\ \text{After 4 hours} & 96 & 32 \\ \text{After 5 hours} & 120 & 64  \\ \dots & \dots & \dots\\ \hline \end{array}

    Can you extend and finish it?
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  5. #5
    Newbie sugarT's Avatar
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    Hey there

    for question 2:

    1) ship 1's velocity relative to ship 2 is 32-24 = 8 mi/h. So ship 2 is basically going 8mi/h faster.
    2) ship 2 is behind how many miles? well d = 3 * 24 = 72 miles
    3) now the time it'll take to get to ship 1 = 72/8 = 9 hours.

    EDIT

    you could picture this as:

    ship 1 is stationary 72 miles away. ship 2 is moving 8mi/h. How long would it take ship 2 to get to ship 1?
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