Answer
$a_{10}$ + $b_{10}$ = 2435
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 $r^{n-1}$.
$a_{10}$ = (-5) $(-2)^{10-1}$ = (-5) $(-2)^{9}$ = (-5)$\times$(-512) = 2560
|$b_{n}$| = 10, -5, -20, -35. This is a arithmetic sequence with common difference = -15
By $b_{n}$ = $b_{1}$ + (n - 1) d.
$b_{10}$ = 10 + (10 - 1) (-15) = 10 - 135 = -125
$a_{10}$ + $b_{10}$ = 2560 + (-125) = 2560 - 125 = 2435
