Just add up the lengths of the four sides, and you have the perimeter.
The perimeter is:
(4x-7)*2 + (10x^2+4x-2)*2 =
8x-14 + 20x^2+8x-4 =
20x^2 + 16x - 18
Let the number be Y .
Y is seven
less than 5 times another (let that other be X)
Y=7-5X
sum of both Y and X minus 4 gives one
Y+X-4=1
now solve both equations .
For this case we must simplify the following expression:

We eliminate the parentheses taking into account that:

We add similar terms taking into account that:
Equal signs are added and the same sign is placed.
Different signs are subtracted and the major sign is placed.

Answer:

63. it's a cube so all you have to do is find the surface area of one side and multiply it by 6 (or you can use the actual formula)
side length^2= 8^2=64
64*6=384cm^2