Final answer:
To make m the subject of the equation m - r - t = y, add r and t to both sides of the equation to get m = y + r + t.
Step-by-step explanation:
To make m the subject of the equation m - r - t = y, you need to isolate m on one side of the equation. You can do this by adding r and t to both sides of the equation, which gives you:
m = y + r + t
Now, m is the subject of the equation, which means that m has been solved for in terms of the other variables in the equation.