First of all i think theres a mistakein the question;
i think it is sin θ =

and then sin 30° =

thus θ= 30°
Depending on the way you look at the numbers, they are increasing/decreasing by 0.1.
0.36- 0.1 =0.26
0.26-0.1=0.16
0.16-0.1=0.06
0.06-0.1=-0.04
-0.04-0.1=-0.14
(Or vice versa by adding 0.1 starting with -0.14)
Make sense?
2(-20)+3[5/4(-20)]
-40 + 3[-25]
-40 + -75
-115
-115 is your final answer.
When divided by 5, 3 subtracted from x divided by 2 equals to 6