Question

How do i find the vertex of the equation y=(x+5)(x+4)?

Answer 1

Explanation:

y=(x+5)(x+4)=x²+5x+4x+20=x²+9x+20=x²+9x+(9/2)²-(9/2)²+20

`y=(x+(9)/(2) )^2-(81)/(4) +20\\y=(x+(9)/(2))^2-(81)/(4)+(80)/(4)\\y=(x+(9)/(2))^2-(1)/(4)`

vertex is (9/2,-1/4) or(4.5,-0.25)