1/4x+1/x=5/16)2)1/x-1/9х=2/9
1/4x+1/x=5/16 1/x-1/9x=2/9 1/4x+4/4x=5/16 9/9x-1/9x=2/9 5/4x=5/16 8/9x=2/9 20x=80 18x=72 x=4 x=4