Given the sequence, the rule appears to be 2n. (Y-1)2 must be distributed. The result is 2Y - 2. 2(2Y-2) = 4Y-4. 2(4Y - 4) = 8Y - 8. The same rule will apply throughout the sequence. 2(8Y-8) must be distributed. To distribute we multiply the outside number (2) by the inside numbers (8Y-8). (2x8Y) + (2x-8) 16Y - 16 is our result. Hope this helps!