Answer:
r(n)=3n-1
Step-by-step explanation:
To fill the squares look for the one filled in column/row/diagonal and figure out its sum.
All other columns/rows/diagonals must be equal to that, so whenever there is a column/row/diagonal with a single missing value you can add the others up and calculate the missing value.
So you have to find those single missing value columns/rows/diagonals, fill them out and continue with the next one until the whole square is filled in.
3 16
Explanation
Factor the numerator and denominator and cancel the common factors.
The area of a rhombus is half of the product of the lengths of the diagonals.
area = (7.5 yd + 7.5 yd)(13 yd + 13 yd)/2
area = (15 yd)(26 yd)/2
area = 390 yd^2/2
area = 195 yd^2
Answer: 195