1 36/(x-0.3)-36/x=4
9/(x-0.3)-9/x=1
9x-9(x-0.3)=x(x-0.3)
x^2-0.3x-2.7=0
10x^2-3x-27=0
(2x+3)(5x-9)=0
x1=-3/2,x2=9/5
2 x/7+72=7x-72
48x/7=144
x=21