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May 20th, 2015, 05:01 AM   #1
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multiply the fractions and make the answer as easy as possible (almost done)

1.32 D) a^2-b^2/2x^2-2y^2 * x+y/3a-3b = a^2-b^2*x+y/2x^2-2y^2*3a*3b
What happens now is that you shorten the fraction, you shorten a and b to remove the 3a and 3b to be 3 and 3. You shorten the fraction of x and y to remove them and make 2x^2 - 2y^2 to be 2x - 2y.
What happens now is this a-b/2x-2y*3*3 What you do now is multiply 2x with 3 and multiply 2y with 3 = a+b/2*3*x-2*3*y Making it = a+b/6x-6y. To end it with a+b/6(x-y).

I am done with the task, but there are one thing I don't understand. Why and how did a-b change into a+b? After I know this, I understand the whole task.

Last edited by skipjack; May 20th, 2015 at 12:19 PM.
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May 20th, 2015, 10:01 AM   #2
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You've been told a few times to use BRACKETS when necessary;
do you not understand what that means?

For example, your "a^2-b^2/2x^2-2y^2 * x+y/3a-3b"
should be: (a^2 - b^2) / (2x^2 - 2y^2) * (x + y) / (3a-3b)

Make SURE you understand why...else you'll keep being in trouble...

The (a - b) did NOT change into (a + b).
What happened is the (a - b)'s all cancelled out,
but the (a + b) didn't.
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May 21st, 2015, 02:18 AM   #3
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Quote:
Originally Posted by Denis View Post
You've been told a few times to use BRACKETS when necessary;
do you not understand what that means?

For example, your "a^2-b^2/2x^2-2y^2 * x+y/3a-3b"
should be: (a^2 - b^2) / (2x^2 - 2y^2) * (x + y) / (3a-3b)

Make SURE you understand why...else you'll keep being in trouble...

The (a - b) did NOT change into (a + b).
What happened is the (a - b)'s all cancelled out,
but the (a + b) didn't.
ah, thanks, i understand brackets now.
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