\(2 \, \mathbf{+ \,} 3 = 5\)
\(3 \, \mathbf{+ \,} 4 = 7\)
\(7 \, \mathbf{- \,} 2 = 5\)
\(7 \, \mathbf{+ \,} 2 = 9\)
Ответ: +, +, -, +.