(x+20)/7+x/4.8=45
(x+20)/7+5x/24=45
24(x+20)+7*5x=45*7*24
39x+24*5*4=5*9*7*24
39x+120*4=120*63
39x=120*63-120*4=120*59
x=120*59/39
=40*59/13
=2360/13
=181 7/13