Solve the equation for the given variable.

B=\left(\frac{q+z}{2}\right)m\ \operatorname{for}\ q
q=

2B/m - z

To solve the equation for q, we need to isolate q on one side of the equation.

The equation is:
B = ((q + z) / 2) * m

Step 1: Multiply both sides of the equation by 2 to get rid of the denominator:
2B = (q + z) * m

Step 2: Distribute the m into the parentheses:
2B = qm + zm

Step 3: Subtract zm from both sides of the equation:
2B - zm = qm

Step 4: Factor out q on the right side of the equation:
qm = 2B - zm

Step 5: Divide both sides of the equation by m:
q = (2B - zm) / m

Therefore, the solution for q is:
q = (2B - zm) / m