#y=(5x-1)(x+1) or y = 5x^2+4x-1# Now comparing withh the general form #y=ax^2+bx+c# we get #a=5; b=4 ; c= -1# The x cordinate of Vertex is # =-b/2*a or -4/10 =-2/5# To get y co-ordinate of veryex putting #x= -2/5# in the equation #y = 5*(-2/5)^2+4*(-2/5)-1 = 5*(4/25)-8/5-1= -9/5# So The vertex form is #y=5(x+2/5)^2-9/5#graph{5x^2+4x-1 [-10, 10, -5, 5]}[Answer]