Question 200635
(14-2x)(16-2x)=80
224-32x-28x+4x62=80
4x^2-60x+224-80=0
4x^2-60x+144=0
4(x^2-15x+36)=0
4(x-12)(x-3)=0
x-3=0
x=3 ans. for the width of the margins.
Proof:
(14-2*3)(16-2*3)=80
(14-6)(16-6)=80
8*10=80
80=80