9514 1404 393
Answer:
(x, f(x)) = (1, 6), (2, 11), (3, 18), (4, 27)
Explanation:
Each figure consists of two small squares and a square that has a side length of 1 more than the figure number. That is, ...
f(x) = (x +1)^2 +2
You can count the squares in figures 1-3. Figure 4 will be 2 more squares than 5^2 = 25, so will be 27 squares.
(x, f(x)) = (1, 6), (2, 11), (3, 18), (4, 27)