By quadratic equation x2 + x - 420 ,we get, x= 20 and x=-2. here does it have two solution or one solution ? Share with your friends Share 0 Manbar Singh answered this The given quadratic equation is, x2 + x - 420 = 0⇒x2 + 21x - 20x - 420 = 0⇒xx + 21 - 20x + 21 = 0⇒x - 20x + 21 = 0⇒x - 20 = 0 or x + 21 = 0⇒x = 20 or x = -21So, 20 and -21 are the solutions of the given quadratic equation.Since, Quadratic equation involves a quadratic polynomial of degree 2, so, it hasonly 2 solutions. 1 View Full Answer