If x+a is a factor of x^2+px+q and x^2+px +q then prove that a=n-q/m-p
p(x)= x2+px+q
g(x)= x+a
x = -a
p(-a)= a2-ap+q=0 1st equatioon
p1(x)=x2+mx+n
p1(-a)=a2-am+n=0 2nd equation
on equating 1 and 2
a2-am+n=a2-ap+q
-am+ap=q-n
-a(m-p)=q-n
-a= q-n/m-p
a= n-q/m-p