what is the LCD of x+7/2x^2+7x-15 ; and x-5/2x^2-5x+3?

Question

anonymous · Answer

factor 2x^2+7x-15  = (2x-3)(x-1) 
factor  x-5/2x^2-5x+3 = (2x-3)(x+5)

can you find the LCD now?

anonymous · Answer

Seems more like a GCF than an LCD, doesn't it?  Odd question...

anonymous · Answer

so does this mean that the lcd is (2x-3)(x-1)(x+5)?

anonymous · Answer

I suppose so.  If you had fractions where the first fraction had the first expression as a denominator and the 2nd fraction had the 2nd expression as its denominator, then the LCD would be the expression you just wrote...

anonymous · Answer

The point, I guess, is that by factoring FIRST, you realize that (2x-3) is actually a common factor, and so you wouldn't multiply by that... if you just multiplied the original expressions together to try to get the LCD, it would be a common denominator, but it wouldn't be the LEAST one... it would be too big by an extra factor of (2x-3)