I have a Dell latitude e7240 that has at least 2 fried caps at the backside of the board near a mosfet i will post an image if anyone can help me because idk the value of the caps photos app goo gl/mWw5AnBmY55hiaLLA
Assuming these caps are related to the mentioned mosfet, then check the datasheet for the said mosfet as it may tell you what those caps should be.
Ah, so after looking at your images you have more serious issues, that trace damage looks deep, time to start scraping and seeing how far the carbon goes 
I’ve just checked and the datasheet doesn’t say. Take off the cap top right which seems fine and measure it’s capacitance, the others will almost certainly be the same value.
Thank you and yes i know that the board is also fried but i don’t think that it is very deep it seems like the cap exploded and fried the zone and i found in a schematic of the board that the caps are 220nf each so i can order them while i fix the board. Thank you for your help
Are you sure? they’re quite chunky to only be 220nf, I mean they might well be but might be worth measuring the one top right just to confirm 
I’d imagine the mosfet/s are bad too