Yes, the equation \(7 - 9 = 7 + (-9)\) is correct.
When you subtract a number, it can be rewritten as adding its negative. Therefore:
\[ 7 - 9 = 7 + (-9) \]
Calculating both sides gives:
\[ 7 - 9 = -2 \]
And
\[ 7 + (-9) = 7 - 9 = -2 \]
So, both sides are equal to \(-2\).