Answer:
1.
2.
3.
4.
5. x =
6. w =
7. n =

Explanation:
1. 45 + 90 + ? = 180
=> ? = 45
2. 60 + 70 + ? = 180
=> ? = 50
3. 85 + 65 + ? = 180
=> ? = 30
4. 104 + 30 + ? = `180
=> ? = 46
5. x + x + (x+3) = 180
=> 3x + 3 = 180
3x = 180 - 3 = 177
x = 177 : 3 = 59
=> angle (x + 3) = 59 + 3 = 62
6. w + w + (4w - 6) = 180
=> 6w - 6 = 180
6w = 180+6 = 186
w = 186 : 6 = 31
=> angle (4w-6) = 4 x 31 - 6 = 118
7. n + n + 50 = 180
=> 2n = 180 - 50
2n = 130
n = 130 : 2 = 65