Answer: - 36
Step-by-step explanation: if you do 21 ÷ -75 and that is 63 and you would put the three at the top and sub -75 and 63 and that is 12 and then you need to drop the 6 and that 126 so if you do 21 x 6 and that is 126 then sub that and - 36 is the answer