The answer is D)6x2 square units.
A surface area of a cube is a sum of its sides' areas. A side of the cube is a square, and there are total 6 sides of the cube. Also, an area of the side of the cube is the area of the square, which can be expressed as a², where a is the length of the side. Therefore, the surface area (SA) of the cube is:
SA = 6*a² = 6a²
If side length is x, that means that a = x units.
After replacing it in the formula, you will have:
SA = 6a² = 6x² square units
The decimal 68.145 written as a fraction is 68145/1000
To divide exponents they have to have the same base and then you just subtract the bottom exponent from the top exponent.
7) k × 3^9
----------- =
3^5
k × 3^9-5 =
k × 3^4 =
k × 81 = 81k
8) x^4 × y^10 × 2^11
------------------------ =
y^8 × 2^7
x^4 × y^10-8 × 2^11-7 =
x^4 × y^2 × 2^4 =
x^4 × y^2 × 16=
16x^4y^2