ALGEBRAIC FRACTIONS 1. Simplify https://media.glynlyon.com/g_alg02_2012/5/2019.gif a) 1/2 b)3m / 3m + 2 c) m - 1 / 3m + 2 2. Simplify the expression. https://media.glynlyon.com/g_alg02_2012/5/269.gif a) -y / x b) y / y - x c) y - x / y 3. Change the mixed expressions to fractions. https://media.glynlyon.com/g_alg02_2012/5/2016.gif a) y^2 - y + 1 / y + 3 b) y^2 + 2y - 8 / y + 3 c) y^2 + 2y - 2 / y + 3 4. Change the mixed expressions to fractions. https://media.glynlyon.com/g_alg02_2012/5/2017.gif a) 11 - 15a / 7a - 5 b) 11a + 9 / 5 - 7a c) 6a - 7 / 7a - 5 5. https://media.glynlyon.com/g_alg02_2012/5/2012.gif a) 2y^2 + 2xy + x - y / x^2 - y^2 b) 3x / x^2 - y^2 c)2xy + x - y / x^2 - y^2
Okay, so yesterday, I showed you a really simple technique for determining which solution was correct. However, this only works under circumstances where you have the potential solution. So, if I asked you to find the answer through simplification for #1, could you do that?
1 / 2
Nope. Lets start at the beginning. \[\frac{\frac{m-2}{m+1}+2}{1+\frac{1+2m}{m+1}}\] Remember when I said that it was easier to deal with everything as a fraction? This is one of those times. How can we get: \[ \frac{m-2}{m+1}+2 \] to add together?
They need to have the same denominator, correct?
yes
so, how do we get 2 to have a denominator of m+1?
do you know that it's okay to multiply any term by 1, and it won't change its value, right?
yes
well, does: \[1=\frac{m+1}{m+1}\] ?
yes
so what happens if you multiply: \[2*\frac{m+1}{m+1}\] ?
3m+2??
hmm... would it be possible to show me your work?
2m+ 1
\[\frac{m-2}{m+1}+2*\frac{m+1}{m+1}\] = ?
m-1 / 3m+2
\[\frac{m-2}{m+1}+\frac{2m+2}{m+1}\] see how I got that?
for the numerator?
yes im am so sorry for confusing you as you can see i am not the best in math lol
That's okay, lol. So you see, it's possible to put the whole numerator into a single fraction without changing its value simply by multiplying one of it's terms by 1 (which is the same as (m+1)/(m+1)). This is a very powerful and simply way to get things to have the same denominator so you can add them. Can the same thing be done with the denominator: \[1+\frac{1+2m}{m+1}\] Can you add the 1 to (1+2m)/(m+1) like I showed you?
3m+ 2 / m+ 1
correct; so on the top, you have: 3m/m+1 and on the bottom you have 3m+2/m+1 What can you do to remove the m+1 from both the numerator and the denominator?
eliminate
lol, yep. To do so: \[\frac{\frac{3m}{m+1}}{\frac{3m+2}{m+1}}*\frac{m+1}{m+1}\] See, it's the same thing as multiplying by 1 again!
so, what's our answer?
m - 1 /3m+2
look at the last equation I gave you. Look at the numerator in the numerator, and the numerator in the denominator.
yea yea 3m / 3m+2
lol, yeah.
so, that's the answer.
whew!! lol
lol, yeah. Algebra II is not for the faint of heart. The second one can be approached in almost the same manner.
OK
So, first add the terms in the numerator together. Multiply the terms by 1 to get the same denominator if necessary. Then do the same with the terms in the denominator of our question.
so what do you get in the numerator when you add the terms together?
is the awnser B?
... yes, it's B.
yayy on to #3
is the awnser A?
You might want to re-check your math on that.
C
How did you get C?
i see my mistake
i multiplied instead of dividing
can we go to #4 now
sure... fortunately, 4 isn't too hard by relative standards.
ok lets go :)
so, what is necessary to be able to add (6a-4)/(7a-5) to 3?
hmmmm....
they need to have the same denominator. So how do we get 3 to have a denominator of (7a-5)?
divide
\[3*\frac{(7a-5)}{(7a-5)}\] See? Multiply by 1? That will convert the 3 to an expresion that has the same denominator as the first term, (6a-4)/(7a-5)
the final awnser is (6a-4)/(7a-5)
So then it becomes: \[\frac{6a-4}{7a-5} - \frac{21a-15}{7a-5}\]
\[\frac{6a-4-21a-15}{7a-5}\]
sorry, plus 15 (+15).
which simplifies to: \[\frac{-15a+11}{7a-5}\]
switch the order of the 2 terms in the numerator, and that's the answer.
yayy thanks can we go on to #5
i got c am i correct?
C
you are correct, lol
Yayyy!!
CAN we do the other 5
The last one was a tricky one, but you managed... do you really need my help?
YESSS
lol
Let's see the problems.
1. Simplify https://media.glynlyon.com/g_alg02_2012/5/276.gif a) a - b b) a - b / a c) -ab / a + b 2. https://media.glynlyon.com/g_alg02_2012/5/209.gif a) 3a+2b+c / abc b) 6 / abc c) 8 3. https://media.glynlyon.com/g_alg02_2012/5/2013.gif a) 2a^2 - 6a + 15 / 8a^2 - 22a + 15 b) -3 / 7 c) 1 / 2a - 3 4. Find the lowest common denominator for the fractions shown. https://media.glynlyon.com/g_alg02_2012/5/205b.gif a) a³ - 1 b) (a³ - 1)(a²+a+1) c) (a + 1)²(a - 1) 5. Simplify the expression. https://media.glynlyon.com/g_alg02_2012/5/303.gif a) -5x^2 - 2x / x^3 - 1 b) x / x^3 - 1 c) -x^2 + 2x / x^3 - 1
#1 looks almost identical to the first one we did the other day.
it does
In fact, I think the answer is the same.
what was the awnser for that one
what did you get?
a -b / a
am i correct?
nope.
-ab / a+b
C
...
im wrong
is it a-b?
well, it is the only remaining answer... listen, I can't really help you if you don't show me your work or your thinking... and if I just kinda give you the answer after you guess the 2 wrong ones, I'm not really helping...
ok
ok for this quiz can i get the answers to them
and for the lessons can you tutor me with them
because the quizzes & tests have time limits with them and with the lessons i can take all the time i want (its so silly for the website to do that)
please
what do you think the answer for #2 is?
B
well, I can tell you your off.
B is not right.
ok hold on
3a+2b+c/
abc
yep, that's more like it.
Sweet :) is #3 C
sorry, this one is a little harder lol, so, I'm not quite sure yet... but almost
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