Answer:
42 square yards
Step-by-step explanation:
T.S.A of cube

where l = 7yd

thus, the surface area of cube is 42 square yards
67.8: 6.78, 0.678, 0.0677
456.8: 45.68, 4.568, 0.4568
531.20: 53.12, 5.312, 0.5312
The pattern here is that the number of 0s there are in the digit of whatever you are dividing by, that is how many places you move the decimal place to the right. For example, by dividing 67.8 by 100, the decimal place has been moved 2 places to the right, resulting in the number 0.678
The quadratic formula is -b plus minus the square root of b^2-4ac all over 2a.
Here, a=1, b=13, and c=30.
The only option that fills in the values correctly is D
15.40 times 0.15
= $2.31 tip