Answer:
1.
x+64°+47°+74°=180°[sum of interior angle of a triangle ]
x+185°=180°
x=180°-185°
x= -5°
2.
5x+5+80°+60°=180°[sum of interior angle of a triangle ]
5x+145°=180°
5x=180°-145°
5x=35°
x=35°/5
x=7°
3.
(5x+1)°+(x+23)°=180°[linear pair]
5x+1°+x+23°=180°
6x+24°=180°
6x=180°-24°
x=156/6
x=26°
4.
4x°+40°=180°[linear pair]
4x°=180°-40°
4x°=140°
x=35°
5.
(4x+3)°=71°[vertically opposite angle]
4x+3°=71°
4x=71°-3°
4x=68°
x=68°/4
x=17°
6.
(4x+3)°=55°[vertically opposite angle]
4x+3°=55°
4x=55°-3°
x=52°/4
x=13°
7.
(x+21)°+2x°=90°[right angle]
3x°+21°=90°
3x°=90°-21°
x°=69°/3
x=23°
8.
(3x+1)°+26°=90°[right angle]
3x+27°=90°
3x=90°-27°
x=63/3
x=21°