What is the vertex form of # y= (x+4)(3x-4)+2x^2-4x#?

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Answer 1 · 2018-06-15T01:04:07

vertex is #(-2/5,-84/5)#

#y=(x+4)(3x-4)+2x^2-4x#

#y=3x^2+8x-16+2x^2-4x#

#y=5x^2+4x-16#

The vertex is given by #x=-b/(2a)# where the quadratic equation is given by #y=ax^2+bx+c#

#x=-b/(2a) = -4/(2times5)=-4/10=-2/5#

Sub #x=-2/5# into equation to get the y-value

#y=5(-2/5)^2+4(-2/5)-16#

#y=-84/5#

Therefore, your vertex is #(-2/5,-84/5)#