Answer: The required value of a is \(\dfrac{3}{2}b.\)
Step-by-step explanation: We are given to solve the following equation for variable a :
\(7a-2b=5a+b~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)\)
To solve the above equation for a, we need to take terms involving a on one side of equality that that involving b on the other side.
So, from equation (i), we get
\(7a-2b=5a+b\\\\\Rightarrow 7a-5a=b+2b\\\\\Rightarrow 2a=3b\\\\\Rightarrow a=\dfrac{3}{2}b.\)
Thus, the required value of a is \(\dfrac{3}{2}b.\)