## Algebra and Trigonometry 10th Edition

$\approx1091.$
Let's compare $f(x)=2x^2+12x$ to $f(x)=ax^2+bx+c$. We can see that a=0.055, b=-120, c=70000. a>0, hence the graph opens up, hence its vertex is a minimum. The minimum value is at $x=-\frac{b}{2a}=-\frac{-120}{2\cdot 0.055}\approx1091.$