All angles in a triangle should equal 180° so I'll give the different equations and solve them
17) 55+54+x+74=180
183+x=180
subtract 183 on both sides
-3°=x
18) 70+60+8x+2=180
132+8x=180
subtract 132 on both sides
48=8x
x=6°
those are the first two
wish I could help more:(