add or subtract

Question

2 2
(2t -8t)+ (8t + 9t)

second question
3 2 3
(t +8t ) + (-3t )

please helpp its urgent i have the answer butt im not suree pleasee helpp

Answer 1

(2t - 8t)+ (8t + 9t)
2t - 8t + 8t + 9t
2t + 9t = 11t

(t +8t ) + (-3t )
t + 8t - 3t
9t - 3t = 6t