If (Z -3) is a factor of Z^3 + aZ^2 + bZ + 18 and a + b = -7, find a and b.
NO SPAMMING
Answers
Answered by
1
Step-by-step explanation:
see the above attachement
Attachments:
Answered by
1
Step-by-step explanation:
if (Z-3) is factor then.
z-3=0.
z= 3.
putting z= 3 in eq.
z^3+az^2+bz+18.=0
(3)^3+a(3)^2+b(3)+18.=0
27+9a+3b+18=0
9a+3b+45=0
3(3a+b+15)=0.
3a+b= -15.........(i).
as given in question ,
a+b=-7/.........(ii).
subtract eq(ii) from (i).
3a+b=-15.
a+b =-7.
(-). (-). (+).
---------------------
2a= -8.
a= -4.
put a=-4 in eq.(i).
a+b =-7
-4+b =-7.
b= -7+4.
b = -3
hence a=-4. and b=-3
Similar questions