Question

If the equations x^2+px+q=0 and x^2+bx+c=0 have 1 common root, then it is equal to??


Ans.-[(q-c)/(p-b)]

Answer 1

x^2+px+q-(x^2+bx+c)=px+q-bx-c=0
x=-[(q-c)/(p-b)]

Answer 2

let a be common root..
then:
a^2 +pa + q =0 and a^2 +ab +c=0
subtracting both :
you get a = your ans