Question 285858
14*20=280 in^2 for the frame.
(14-2x)(20-2x)=160
280-40x-28x+4x^2=160
-4x^2-68x+280-160=0
-4x^2-68x+120=0
-4(x^2+17x-30)=0
-4(x-15)(x-2)-0
x-2=0
x=2cm ans. for the width of the frame.Proof:
(14-2*2)(20-2*2)=160
(14-4)(20-4)=160
10*16=160
160=160