For example, for LCM (12,30) we find:
Using the set of prime numbers from each set with the highest exponent value we take 22 * 31 * 51 = 60. Therefore LCM (12,30) = 60.
108=2x-4(2x-9)
108=2x-8x+36
108=-6x+36
-36 -36
72=-6x
72/-6=-6x/-6
-12=x
The trapezoid has one pair of parallel sides.