8x
x=12
8·12
storage space equals 96
since the storage space is only 15% of the total space (100), then that means there is 85% space left needed, to get the other 85 percent you then need to divide 100 by 15 which is 6.6666
after that you then multiply 6.6666 by 96 because the storage space is 15% of the garage and that is the 15%.
the total garage space is 640 ft²