Answer:
Step-by-step explanation:
xy=96
y=96/x
A=(x+4)(y+6), using y=96/x we have
A=(x+4)(96/x+6)
A=(x+4)(96+6x)/x
A=(96x+6x^2+384+24x)/x
A=(6x^2+120x+384)/x
dA=(12x^2+120x-6x^2-120x-384)/x
dA=(6x^2-384)/x^2
dA=0 when
6x^2=384
x^2=64
x=8, y=96/x=12
The overall dimensions are x+4 and y+6
A width of 12cm and a height of 18cm (with a minimum area of 216 cm^2)