(х+2 5/6)/20+7 1/ 5 =7 1/2
(х+2 5/6)/20+7 1/5=7 1/2 (х+2 5/6)/20=7 1/2-7 1/5 (х+2 5/6)/20=7 5/10-7 2/10 (х+2 5/6)/20=3/10 х+2 5/6=3/10×20 х+2 5/6=3×2 х+2 5/6=6 х=6-2 5/6 х=5 6/6-2 5/6 х=3 1/6