if x-a is a factor of 3x2-mx-na then prove that a=m+n/3 Share with your friends Share 7 Renu Sharma answered this As x-a is a factor of 3x2 -mx -na, then it would satisfy the polynomial 3x2 -mx -na, that means the value of the polynomial at x=a would be 0.so lets plug x=a in the given polynomial 3x2 -mx -na⇒3a2 -ma -na=0⇒a(3a -m -n)=0we can take (3a -m -n)=0 3a = m + n a= m+n3 Hence Proved. 17 View Full Answer