Question

determinati a apartine lei R pt care propozitiile de mai jos sunt adevarate  
a)ecuatia 2x+a=0 are solutia x=-5
b)ecuatia -ax +12=0 are solutia x=1

Answer 1

2x+a=0
x=-5
2*-5+a=0
-10+a=0
a=10

-ax+12=0
x=1
-a*1+12=0
-a=-12 /-1
a=12