Answer:
[tex]\large\boxed{a=\dfrac{3b}{2}=\dfrac{3}{2}b=1.5b}[/tex]
Step-by-step explanation:
[tex]7a-2b=5a+b\qquad\text{add}\ 2b\ \text{to both sides}\\\\7a-2b+2b=5a+b+2b\\\\7a=5a+3b\qquad\text{subtract}\ 5a\ \text{from both sides}\\\\7a-5a=5a-5a+3b\\\\2a=3b\qquad\text{divide both sides by 2}\\\\\dfrac{2a}{2}=\dfrac{3b}{2}\\\\a=\dfrac{3b}{2}[/tex]
