Homework Help: Help1

Posted by Allen on Friday, October 13, 2006 at 1:33pm.

WHY rational expressions that are being added must have an LCD, but rational expressions that are being multiplied do not need to have an LCD.

The short answer is that addition and multiplication are different operations with different properties.
If we added rational expressions directly without using the LCD the answer would be nonsense. Consider this
1/2 + 1/2 = (1+1)/(2+2) = 2/4 = 1/2 ??
Does that make any sense?
We know the right answer should be 1/2 + 1/2 = 1.

No one has answered this question yet.

Answer this Question

Related Questions

algebra - Find the LCD for the given rational expressions, and convert each ...
Algerbra 1 - 1/3x + 5/6 = 2/9x - 1/3 How do I solve this to get the answer? For ...
rational expressions - I was asked how rational expressions might be used in my ...
Math - what you have learned about rational expressions and their applications, ...
Math - When adding and subtracting rational expressions, why do you need a LCD?
algebra - what are rational expressions? Why must we always be mindful of the ...
algebra - find the lcd of the rational expressions 1/35r, (r+3)/10r^2
Algebra - Find the LCD for the given rational expressions, and convert each ...
math - Why is it important to simplify radical expressions before adding or ...
Algebra - *correction of previous post* Find the LCD of the rational expressions...

For Further Reading

First Name:
School Subject:
Answer: