Question

Determinati "a" apartine lui R pentru care enunturile de mai jos devin adevarate:
2x+a=0 are solutia 2
ax+a+1=0 are solutia 2
-ax+12=0 are solutia 1
3x-a+2 =0 are solutia 1/3

Answer 1

1) solutia=2 → x=2
2*2+a=0
4+a=0
a=-4 (apartine lui R)

2) solutia=2 → x=2
ax+a+1=0
2a+a+1=0
3a+1=0
3a=-1
a= -⅓ (apartine lui R)

3) solutia=1 →x=1
-ax+12=0
-a*1+12=0
-a+12=0
-a=-12
a=12 (apartine lui R)

4) solutia=⅓
3x-a+2=0
3*⅓-a+2=0
1-a+2=0
3-a=0
-a=-3
a=3 (apartine lui R)