Answer:
Step-by-step explanation:
y=(x+5)(x+4)=x²+5x+4x+20=x²+9x+20=x²+9x+(9/2)²-(9/2)²+20
[tex]y=(x+\frac{9}{2} )^2-\frac{81}{4} +20\\y=(x+\frac{9}{2})^2-\frac{81}{4}+\frac{80}{4}\\y=(x+\frac{9}{2})^2-\frac{1}{4}[/tex]
vertex is (9/2,-1/4) or(4.5,-0.25)
