Answer :

Question 1

[tex]\angle 1[/tex] and [tex]\angle 2[/tex] are supplementary.

[tex]3x+20+x=180 \\ \\ 4x+20=180 \\ \\ 4x=160 \\ \\ x=40[/tex]

[tex]\angle 1[/tex] and [tex]\angle 4[/tex] are vertical angles. Thus, [tex]m\angle 4=3(40)+20=140^{\circ}[/tex].

Question 4

[tex]105+3x=180 \\ \\ 3x=75 \\ \\ x=25[/tex]