Answer:
[tex]85^\circ[/tex]
Step-by-step explanation:
[tex]\text{1. }5x^\circ=2x^\circ+57^\circ\ \ \ [\text{An exterior angle of a triangle is equal to the sum of }\\\text{}\qquad\qquad\qquad\qquad\qquad\text{the opposite interior angles.]}\\\text{or, }3x^\circ=57^\circ\\\text{or, }x=19^\circ[/tex]
[tex]\text{2. }a+5x=180^\circ\ \ [\text{Sum of angles in straight line is 180}^\circ.]\\\text{or, }a+5(19^\circ)=180^\circ\\\text{or, }a=180^\circ-95^\circ\\\text{or, }a=85^\circ[/tex]
