Question

I got it wrong on my quiz, my exam is tomorrow and id like help understanding it.

Answer 1

The perimeter of the sandwich is the sum of all its sides, then we have:

$2x^2+8+2x^2+8+2x^2+9+2x^2+9=8x^2+34$

Therefore the perimeter is:

$8x^2+34$

The length of the crust is the same as the perimeter of the sandwich; if x=1.2 we have that:

$8(1.2)^2+34=45.52$

Therefore the length of the crust is 45.52