Answer:
d. 18
Explanation:
Lengths AG and CF of the parallelogram are equal.
i.e AG = CF
where AG = 2x + 10
CF = 5x -2
→ 2x + 10 = 5x-2
(collecting like terms): 5x - 2x = 10 + 2
→ 3x = 12
x=12÷3 = 4
∴ CF = 5x -2 = 5(4) -2 = 20 - 2 = 18
∴ CF = 18 (answer)