Remember: Divide numbers like normal, then add the positive or negative sign! Two of the same sign (ex <em>-neg </em>÷ <em>-neg</em> or<em> +pos </em>÷ <em>+pos</em>) always equals a positive number. Two different signs (ex<em> -neg </em>÷<em> +pos </em>or<em> +pos </em>÷<em> -neg</em>) always equals a negative number.
You use x= -b/2a in order to get your maximum so x= -10/ 2(-5) and you get x=1. You plug 1 into the function as h(1)=-5(1)^2 + 10(1)+ 20 which gets you 25
