-21+56:7

To solve the expression \(-21 + 56 : 7\), we first perform the division before the addition, according to the order of operations.

1. Calculate \(56 : 7\): \[ 56 \div 7 = 8 \]

2. Now, substitute this value back into the expression: \[ -21 + 8 \]

3. Finally, perform the addition: \[ -21 + 8 = -13 \]

Therefore, the result of \(-21 + 56 : 7\) is \(-13\).