Question 86120This question is from textbook introductory algebra
: 1. How do I perform the indicated operation?
3 5
___ - ___
2b 3b^3
2. Subtraction:
_____2x____ - ___7___
x^2-13x+42 x-6
3. Find LCD:
_____7_____, ___8___
a^2+2a-63 a+9
4. Perform the indicated operation. Simplify if possible.
___6a^2-8a-8___ / ___a-2___
2a^2-9a-56 a-8
Thanks!
This question is from textbook introductory algebra
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 1. How do I perform the indicated operation?
3 5
___ - ___
2b 3b^3
---------
lcd = 6b^3
Rewrite each fraction with the lcd as its denominator:
----------
= 9b^2/lcd - 10/lcd
------------
Combine the numerators to get:
= [9b^2-10]/6b^3
=======================
2. Subtraction:
_____2x____ - ___7___
x^2-13x+42 x-6
----------
lcd = (x-6)(x-7)
Rewrite:
[2x/lcd] - [7(x-7)/lcd]
---------
Combine:
= [2x-7x+49]/lcd
= [-5x+49]/[x^2-13x+42]
=============
3. Find LCD:
_____7_____, ___8___
a^2+2a-63 a+9
---------------
Rewrite:
7/[(a+9)(a-7)], 8/(a+9)
------------
LCD = (a+9)(a-7)
===================
4. Perform the indicated operation. Simplify if possible.
___6a^2-8a-8___ / ___a-2___
2a^2-9a-56 a-8
---------
Factor where you can to get:
[2(a-2)(3a+2)/(a-8)(2a+7)]
Cancel where you can to get:
=[2(3a+2)/(2a+7)]
===================
Cheers,
Stan H.
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