Question

Answer 1

\(a,\left(-12\right)+19=7\\ \left(-23\right)+\left(-47\right)=-23-47=-70\\ \left(-18\right)-\left(-9\right)=-18+9=-9\\ \left(-32\right)+\left(-42\right)=-32-42=-74\\ ----------\\ b,\left(-1654\right)+654-100=-1000-100=-1100\)

Answer 2

a) \(\left(-12\right)+19=19-12=7\)

\(\left(-23\right)+\left(-47\right)=-\left(23+47\right)=-70\)

\(\left(-18\right)-\left(-9\right)=-18+9=-\left(18-9\right)=-9\)

\(\left(-32\right)+\left(-42\right)=-\left(32+42\right)=-74\)

b) \(\left(-1654\right)+654-100=-\left(1654-654\right)-100=-1000-100=-\left(1000+100\right)=-1100\)

Answer 3

\(a,\left(-12\right)+19=19-12=7\)

\(\left(-23\right)+\left(-47\right)=-\left(23+47\right)=-70\)

\(\left(-18\right)-\left(-9\right)=\left(-18\right)+9=-\left(18-9\right)=-9\)

\(\left(-32\right)+\left(-42\right)=-\left(32+42\right)=-74\)

\(b,\left(-1654\right)+654-100=\left(-1654+654\right)-100=-\left(1654-654\right)-100=-1000-100=-1100\)