Răspunsuri

2014-02-27T20:45:25+02:00
(2a-20)/30+13= b
75/b = 5  b = 15  
(2a-20)/30+13=15    (2a-20)/30=2  2a-20=60    2a=80  a=40
2 1 2
2014-02-27T20:50:34+02:00
[(2x-20):30+13]:75=5
(2x-20):30+13=375
(2x+20):30=362 x 30
2x+20 =10860
2x=10840
x=5420