Answer
$a_{11}$ + $b_{11}$ = -5260
Work Step by Step
Given sequence
|$a_{n}$| = -5, 10, -20, 40. This is a geometric sequence with common ratio = -2
By $a_{n}$ = a $r^{n-1}$.
$a_{11}$ = (-5) $(-2)^{11-1}$ = (-5) $(-2)^{10}$ = (-5)$\times$(1024) = -5120
|$b_{n}$| = 10, -5, -20, -35. This is a arithmetic sequence with common difference = -15
By $b_{n}$ = $b_{1}$ + (n - 1) d.
$b_{11}$ = 10 + (11 - 1) (-15) = 10 - 150 = -140
$a_{11}$ + $b_{11}$ = -5120 -140 = -5260