BCLN's Physics. Equation solving and rearranging.

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0:00one of the most challenging parts of
0:03this introductory unit particularly if
0:06it's been a little while since you
0:07finished your math 10 / requisite is
0:10equation solving or rearranging formula
0:14i'll give you a quick overview of this
0:17concept here then we'll include some
0:20other examples later in your math
0:24classes you solved the equations for a
0:27variable for example 3x plus 2 equals 8
0:32and solve for x we remember that solving
0:37for x means from a conceptual point of
0:40view finding an ex that would make this
0:42equation true if we plug it in or from a
0:46more procedural point of view solving
0:50for x means getting the x all by itself
0:53on one side of the equal sign or
0:56isolating the variable as it sometimes
0:59set so let's hear isolate the X in this
1:06example so to get the X on its own will
1:11first notice that we don't want this to
1:14hear it's not a place where currently
1:17adding the two so to remove it will
1:21simply do the opposite and subtract x 2
1:25now whatever we do to the one side of
1:28the equal sign we also do to the other
1:30so we subtract tattoo over here as well
1:34I like to draw a line across here just
1:37to finish off that step the plus 2 and
1:41the minus 2 on the left
1:42cancel each other out as planned and on
1:46the right we have the 8-2 gives us six
1:51so we're closer to having this X
1:54isolated but to get the X by itself
1:58totally will have to also get rid of
2:01this three here it's also a place where
2:04currently multiplying the X by three so
2:08the opposite of this is dividing by 3
2:11again
2:13whatever we do to the one side we also
2:16do to the other so the threes cancel on
2:20the left here one on the top one on the
2:22bottom and on the right we have the 6/3
2:26gives us to hopefully that all looks
2:32familiar to you
2:33I wanted to start with that and then
2:36move to rearranging when there's
2:38multiple variables as you'll be able to
2:41see that it's the exact same steps so
2:44let's use for example 80 plus V naught
2:48equals V F and we're solving for T so
2:54before we carry on let's just quickly
2:56give you a foreshadow of later units by
2:58pointing out what these variables really
3:00represent so the a represents
3:03acceleration the t represents time V
3:08naught represents the initial or
3:11starting velocity of some object and the
3:14VF represents the final velocity of this
3:16object now you didn't really need to
3:19know that to do this part of the course
3:21but i just wanted to quickly point those
3:24out so back to the rearranging here so
3:27if we compare this equation with our
3:29previous one we can see that they're the
3:33same type of equation
3:35simply stated in the previous example a
3:38was the three the X is now time the
3:45initial velocity V naught was too and
3:49the final velocity was eight so they all
3:52line up here thus solving for T instead
3:57of X and a previous one should be pretty
4:00darn similar
4:03in the previous example we started
4:06isolating the X by noticing that the two
4:09was at a place so we subtracted in this
4:14case the two is instead he not so let's
4:19do the same thing and to get rid of it
4:22we subtract B not now remember whatever
4:25we do to one side we also do to the
4:28other on the left just like before the V
4:33naught and the minus V not cancel each
4:36other out and on the right we have it as
4:39V F minus V naught in the previous
4:45example we could reduce this down to one
4:47number
4:48this is true in this case we have to
4:51leave it as V F minus V not knowing that
4:55we may end up with those numbers later
4:57and then we'll know what to do with them
4:59for now we just have to say VF has to be
5:03subtracted by v naught so we're closer

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