24a6b4 15x-10xy m2-4 16a3b7 5xy 2m-4

24a6b4  / 16a3b7 = (8a3b4 *3a3 ) / ( 8a3b4 * 2b3) = (3a3)  / (2b3) = 3/2 *(a/b)^2 
15x-10xy / 5xy  =5x (3-2y) / 5xy  = (3-2y) / y
 m2-4 /2m-4  = (m+2)(m-2) / 2(m-2) = (m+2) / 2