Răspuns :
a) a(b+c)=36/25
b+c=-12
a×(-12)=36/25
a=-36/25×1/12
a=-3/25
b) a(a+b+c)=2/3
a+b+c=-2
a×(-2)=2/3
a=-2/3×1/2
a=-1/3
-1/3+b+c=-2
b+c=-2+1/3
b+c=-6/3+1/3
b+c=-5/3
c) a²(b-c)=9
b-c=4
a²×4=9
a²=9/4
a1=3/2. si a2=-3/2
a) a(b+c)=36/25
b+c=-12
a×(-12)=36/25
a=-36/25×1/12
a=-3/25
b) a(a+b+c)=2/3
a+b+c=-2
a×(-2)=2/3
a=-2/3×1/2
a=-1/3
-1/3+b+c=-2
b+c=-2+1/3
b+c=-6/3+1/3
b+c=-5/3
c) a²(b-c)=9
b-c=4
a²×4=9
a²=9/4
a1=3/2. si a2=-3/2