c) A division fact of a÷b=c is equivalent to the division fact a÷c=b.
Therefore −8.58÷□=3.9 is equivalent to the division fact −8.58÷3.9=□.
Since −8.58÷3.9=−2.2, then −8.58÷−2.2=3.9.

d) A multiplication fact of a×b=ca×b=c is equivalent to the division fact b=c÷a. Therefore −3.2×□=24 is equivalent to the division fact □=24÷(−3.2)□. Since 24÷(−3.2)=−7.524÷(−3.2)=−7.5, then −3.2×−7.5=24.

d) A multiplication fact of a×b=ca×b=c is equivalent to the division fact b=c÷a. Therefore −3.2×□=24 is equivalent to the division fact □=24÷(−3.2)□. Since 24÷(−3.2)=−7.524÷(−3.2)=−7.5, then −3.2×−7.5=24.