Q . the value of 'b' for which equations x2+bx-1=0 x2+x+b=0 have one root in common is ?? Share with your friends Share 16 Priyanka Kedia answered this The given equation be as,x2+bx-1=0 .....1x2+x+b=0 .....2Let α be the common root. So, α satisfies both the equations.α2+bα-1=0 .....3α2+α+b=0 .....4Subtracting equation 3 and 4, we have,αb-1-1-b=0⇒α=1+bb-1Substitute value of α in equation3, we have, 1+bb-12+b1+bb-1-1=0⇒1+b2+bb2-1-b-12=0⇒ b3+3b=0⇒bb2+3=0⇒b=0,±3i 35 View Full Answer