Răspunsuri

2014-03-26T19:45:44+02:00


5:(3a-10)+20=r:3=9

r=27

(3a-10)+20=27*5=135

3a-10=115

3a=125

2014-03-26T21:13:48+02:00
[(3a-10):5 +20]:3=9
(3a-10):5+20=27
(3a-10):5=7
3a-10=35
3a=45
a=15