Question

Rezolvați in Mulțimea numerelor reale ecuațiilor :a)2[3(4x+5)-6]=12;b)1/3[2+5(x/3+1)]=-4

Answer 1

a)2[3(4x+5)-6]=12
[3(4x+5)-6]=12:2
3(4x+5)-6=6
3(4x+5)=6+6
3(4x+5)=12
4x+5=12:3
4x+5=4
4x=4-5
4x=-1
x=-1/4=-0,25

1/3[2+5(x/3+1)]=-4
[2+5(x/3+1)]=-4x3
2+5(x/3+1)=-12
2+5x/3+5=-12
5x/3+7=-12
5x/3=-12-7
5x/3=-19
5x=-19x3
5x=-57
x=-57/5=-11,4