Sydney is cutting the crust from the edges of her sandwich. the dimensions, in centimeters, of the sandwich is shown. which expression represents the total perimeter of her sandwich, and if x = 1.2, what is the approximate length of the crust? 8x2 + 34; 43.6 centimeters 8x2 + 34; 45.52 centimeters 4x2 + 17; 21.8 centimeters 4x2 + 17; 22.76 centimeters

The dimensions of the sandwich are 2x^2 + 9 and 2x^2 + 8 so to find the perimeter we have to use the equation 2l+2w

2(2x^2+9) + 2(2x^2+8)

Distribute the 2's through the parentheses

4x^2 + 18 + 8x^2 + 16

Then combine like terms

8x^2 + 34

This equation is shown in both a, and b. So to figure out which is correct we simply substitute 1.2 in for x and solve.

a) 8x^2 + 34 = 43.6
      8(1.44) + 34
       11.52 + 34
          45.52

b) 8x^2 + 34 = 45.52
      8(1.44) + 34
       11.52 + 34
          45.52

Seeing as b equals what it says it will equal, b) 8x^2 + 34 = 45.52 is the correct answer.

Hope this helps!