vertex form is [tex]y=a(x-h)^2+k[/tex]
comlpete the square
[tex]y=5x^2+20x+14[/tex]
group x terms
[tex]y=(5x^2+20x)+14[/tex]
factor quadratic coefient
[tex]y=5(x^2+4x)+14[/tex]
take 1/2 of linear coefient and square it
4/2=2, 2^2=4
add positive and negative of it inside the parentheasees
[tex]y=5(x^2+4x+4-4)+14[/tex]
factor perfect squarer trinomial
[tex]y=5((x+2)^2-4)+14[/tex]
expand
[tex]y=5(x+2)^2-20+14[/tex]
[tex]y=5(x+2)^2-6[/tex] is vertex form
