Question

The roots alpha and beta of the quadratic equ.are : x*x-5x+3(k-1)=0 show that alpha-beta=11then find the value of k

Answer 1

a +b = -b/a then =5
a-b=11 given
then take a=5-b....1 eqn
take a=11+b...2eqn
equating both eqns
5-b=11+b
5=11+2b
2b = -6
b=-3 substitute in 1 eqn we get a=8
then a×b=c/a then -3×8=-24
-24 =3(k-1)
-24/3=(k-1)
-8=k-1
k=-7 substitute in3 (k-1) then -21