Răspunsuri

2014-04-02T23:54:42+03:00
A) 2{3[20x+4-3]-2}=2⇒2{3[20x+1]-2}=2
2{60x+3-2}=2⇒2{60x+1}=2⇒120x+2=2
120x=2-2⇒120x=0⇒x=0
b) {2[14+(5+x)/1·1/6]-5}:9+7=10 
{2[14+(5+x)/6]-5}:9+7=10 aducem paranteza mare la acelasi numitor
{2[(84+5+x)/6]-5}:9+7=10
{2[(89+x)/6]-5}:9+7=10
Obs.{2(89+x)/6 simplificam cu 2
{(89+x)/3-5}:9+7=10 aducem paranteza la acelasi numitor care este 3
{(89+x-15)/3}:9+7=10
{(74+x)/3}·1/9+7=10
(74+x)/27=10-7
(74+x)/27=3
(74+x)=3·27
74+x=81
x=81-74
x=7