42,34,26,18,10,U240?

Jawab: -1870

Penjelasan dengan langkah-langkah:

b = 34-42

b = -8

U240 = a + ( n-1 ) x b

= 42 + (240-1) x (-8)

= 42 + 239 x -8

= 42 + -1912

= -1870