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Oplossen van Een-stap Vergelijkingen 2

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    Solve for x and
    check your solution.
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    We have x divided
    by 3 is equal to 14.
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    So to solve for x, to figure
    out what the variable x must
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    be equal to, we really
    just have to isolate it
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    on the left-hand side
    of this equation.
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    It's already sitting there.
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    We have x divided
    by 3 is equal to 14.
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    We could also write this
    as 1/3 x is equal to 14.
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    Obviously, x times 1/3
    is going to be x/3.
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    These are equivalent.
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    So how can we just end up with
    an x on the left-hand side
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    of either of these equations?
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    These are really the same thing.
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    Or another way, how
    can we just have a 1
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    in front of the x, a 1x,
    which is really just saying
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    x over here?
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    Well, I'm dividing
    it by 3 right now.
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    So if I were to multiply both
    sides of this equation by 3,
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    that would isolate the x.
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    And the reason that would
    work is if I multiply this
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    by 3 over here, I'm multiplying
    by 3 and dividing by 3.
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    That's equivalent.
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    That's equivalent to
    multiplying or dividing by 1.
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    These guys cancel out.
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    Remember, if you do it
    to the left-hand side,
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    you also have to do it
    to the right-hand side.
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    And actually, I'll do
    both of these equations
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    at the same time,
    because they're really
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    the exact same equation.
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    So what are we going to get
    over here on the left-hand side?
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    3 times anything divided by 3
    is going to be that anything.
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    We're just going to
    have an x left over
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    on the left-hand side.
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    And on the right-hand
    side, what's 14 times 3?
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    3 times 10 is 30,
    3 times 4 is 12.
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    So it's going to be 42.
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    So we get x is equal to 42.
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    And the same thing
    would happen here.
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    3 times 1/3 is just 1.
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    So you get 1x is equal to
    14 times 3, which is 42.
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    Now let's just check our answer.
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    Let's substitute 42 into
    our original equation.
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    So we have 42 in place for
    x over 3 is equal to 14.
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    So what's 42 divided by 3?
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    And we could do a little
    bit of-- I guess we call it
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    medium-long division.
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    It's not really long division.
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    3 into 4.
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    3 goes into 4 one time.
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    1 times 3 is 3.
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    You subtract.
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    4 minus 3 is 1.
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    Bring down the 2.
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    3 goes into 12 four times.
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    3 goes into 42 14 times.
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    So this right over
    here simplifies to 14.
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    And it all checks
    out, so we're done.
Title:
Oplossen van Een-stap Vergelijkingen 2
Description:
more » « less
Video Language:
English
Duration:
02:23

English subtitles

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