45-а=9

To solve for \(a\), consider the given equation:

\[ 45 - a = 9 \]

To isolate \(a\), you need to get it alone on one side of the equation. You can do this by adding \(a\) to both sides of the equation to move \(a\) to the right side and at the same time, subtracting 9 from both sides to move the constant term to the left side:

\[ 45 - a + a = 9 + a \] \[ 45 = 9 + a \]

Now subtract 9 from each side:

\[ 45 - 9 = a \] \[ 36 = a \]

Therefore, \(a = 36\).