Neeed help urgent!

Aight so i was gone for a week and foundm one of my plants with white spots on it and dont know what it is.... And the other one I was already having problem with it getting yellowish, the lower older leaf already died and now is spreading to the upper leaf, what is it?
Sorry for the bad quality of the pics but they are as good as I can get...

The brown tips of the leaves are from overfertilizing and I can't see more than that in your pictures. If you mean you have light colored areas it's probably nutrient lockout because the PH is way off. Flush that baby with about two gallons of clean PH'D aired out water and see if it doesn't turn around.

The only other spots I can guess you might have is spider mites. You can google spider mite damage and compare pics to be sure, or look it over with a good magnifying glass and see if you don't see almost microscopic little bugs moving around on the underside of the leaves.

my poor little girl got flushed just a week and a half ago... oh man i swear i will never use fking Miracle Grow soil again, i think it is because it has all the chemicals shit that feed the plant for 3 months... 3 of my babies died already.. and now these two are going in the same way =(