To solve this problem you must apply the proccedure shown below: 
 1. You have the following expression given in the problem above:
 x²-10xy+24y²
 2. When you factor the expression x²-10xy+24y², you obtain the following:
 (x-4y)(x-6y)
 3. To verify the result you can apply the distributive property and the result must be x²-10xy+24y².
 Therefore, the answer is: (x-4y)(x-6y)