(x+2)*(96-2x)

=96x+192-2x^2-4x

=-2x^2+92x+192

=-2(x^2-46x-96)

=-2((x-23)^2+(529+96))

=-2(x-23)^2+1250

.....1250心算錯左><

c.easy

(x-23)^2

x=23

length:96-2(23)=46

width:23+2=25

答左la

on9

john高手