Răspunsuri

Cel mai inteligent răspuns!
2014-10-23T17:12:51+03:00
1)
cu x notez creioanele
cu y notez radierele
cu z notez caietele

3x+5y=13 
4x+2z=8⇒2z=8-4x⇒2z=2(4-2x)⇒z=4-2x

2)
b)3(2x+7)-5=22
6x+21-5=22
6x=22-21+5
6x=6
x=1

5 [2(3x+2)-11]+4 =29
5 [6x+4-11]+4 =29
5 [6x-7]+4 =29
30x-35+4=29
30x=29+35-4
30x=60
x=2
1 5 1