Answer:
[tex]\large\boxed{b=\dfrac{4a+3}{3}}[/tex]
Step-by-step explanation:
[tex]4b+a-3=b+5a\qquad\text{add 3 to both sides}\\\\4b+a-3+3=b+5a+3\\\\4b+a=b+5a+3\qquad\text{subtract}\ a\ \text{from both sides}\\\\4b+a-a=b+5a-a+3\\\\4b=b+4a+3\qquad\text{subtract}\ b\ \text{from both sides}\\\\4b-b=b-b+4a+3\\\\3b=4a+3\qquad\text{divide both sides by 3}\\\\\dfrac{3b}{3}=\dfrac{4a+3}{3}\\\\\boxed{b=\dfrac{4a+3}{3}}[/tex]