Answer:
[tex]45[/tex] degrees
Step-by-step explanation:
Angles on a straight line add up to 180 degrees.
Thus, [tex]x+3x=180[/tex]
[tex]4x=180[/tex]
Divide both sides by 4:
[tex]\frac{4x}{x} =\frac{180}{4}[/tex]
[tex]x=45[/tex]
