Final answer:
To have x as the subject of the formula, subtract y from both sides of the equation, resulting in x = 7 - y.
Step-by-step explanation:
To rearrange the equation y = 7 - x and have x as the subject, you need to isolate x on one side of the equation. Start by subtracting y from both sides:
y - y = 7 - x - y
This simplifies to:
0 = 7 - x - y
Next, rearrange the terms:
x = 7 - y
Now, x is the subject of the formula.
Learn more about Rearranging equations