Friday

December 19, 2014

December 19, 2014

Posted by **Elton** on Tuesday, January 9, 2007 at 11:40pm.

50r^8 – 32r^2

The caret symbol represents a power.

2r^2(25r^6+16)=

2r

DrBob222 forgot a minus sign:

50r^8 – 32r^2 =

2r^2(25r^6 - 16)

Then, inside the brackets, you see a difference of two squares:

25r^6 - 16 = X^2 - Y^2

with X = 5 r^3 and Y = 4

You can then simplify this using

X^2 - Y^2 = (X + Y)(X - Y) --->

25r^6 - 16 = (5 r^3 + 4)(5 r^3 - 4)

You can factor each of these factors further by finding one of the roots.

5 r^3 + 4 = 0 -->

r = -(4/5)^(1/3)

This means that you can divide

5 r^3 + 4 by [r + (4/5)^(1/3)] to obtain a quadratic term. In case of the other factor you find the root

r = (4/5)^(1/3) and you can thus divide the term by [r- (4/5)^(1/3)] to find a quadratic factor.

Thanks to Count Iblis for catching my error. I got so carried away with trying to make the exponents look good that I simply read a minus sign but typed a + sign. Such is old age, bad eyes, and an elevator that doesn't go all the way to the top.

**Answer this Question**

**Related Questions**

Derivatives - What is the fourth derivative of f(x)= e^-x^2. I got f''(x)=-2e^-x...

Powers in Math - (5a^3b^4)^2=? *I don't get this one...PLease Help! (5a3b4)2= (5...

math-volume - I'm confused with how to solve this problem, so help would be ...

help - Y^3Y/Y^-2 If you post with the correct word in the Subject line, you'll ...

mat 117/ algebra - My question is about scientific notations. Here is the ...

Property of logarithms - Using property of logarithms, how do I prove derivative...

algebra2 plzz help - how do you solve these problems (5x)to the power of a+4(5x)...

math2 - 5y^8-125 *you have to factor completley easy. Take out the five: 5(y^8-...

math exponents - x to the - power x to the fraction power x to the -fraction ...

Chemistry - Sorry for posting this again, I dont know if the question was ...