Answer:
3x(2x - 5)
Explanation:
because you have x² that means that you have to timse x by x to get x².
6 divided by 15 gets you a decimal but both number goes into the 3 times table
Therefor 6x² - 15x = 3x(2x-5)
If you need to check just times 2x by 3x which would get you 6x² and 5 by 3x which would get you 15x