x+1/5=1/2=>x=5/10-2/10=>x=3/10(amplificam prima fractie cu 2 si pe a doua cu 5)
x+6/7=20/7=>x=20/6=>x=10/3
x+2/99=0,75/0,25=>x=99/99-2/99=>x=97/99
x-1/2=6*5/3=>x-1/2=10=>x=20/2-1/2=>x=19/2
x-1/2=1/4:2/9=> x-1/2=1*9/4*2=>x=9/8-1/2=>x=5/8
x-23/99=5/2=>x=5/2*99/23=>x=495/46