What is the vertex form of $y=(x+2) (2x+5)$ ?

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Answer 1 · 2017-12-21T22:05:29

$y=2*(x+9/4)^2-1/8$

$y=(x+2)*(2x+5)$

= $2x^2+9x+10$

= $2*(x^2+9/2x+5)$

= $2*(x^2+9/2x+(9/4)^2+5-(9/4)^2)$

= $2*(x^2+9/2x+(9/4)^2-1/16)$

= $2*(x+9/4)^2-1/16)$

= $2*(x+9/4)^2-1/8$

What is the vertex form of y=(x+2) (2x+5) y=(x+2) (2x+5) ?