Cho $a,b \in Z$ và $b \ne 0.$ Nếu có số nguyên $q$ sao cho $a = bq$  thì

$1000$

$ - 1000$

$ - 100$

$ - 10000$

$\left( { - 5} \right).25 =  - 125$                         

$6.\left( { - 15} \right) =  - 90$                            

$125.\left( { - 20} \right) =  - 250$                          

$225.\left( { - 18} \right) =  - 4050$

\( - 6;\,\;6;\;\,0;\,\;23;\, - 23\)

\(132;\, - 132;\;\,16\)  

\( - 1;\,\;1;\,\;6;\, - 6\)  

\(0;\;\,6;\, - 6;\;\,12;\, - 12;\,...\)

\(\left( { - 20} \right).\left( { - 5} \right) =  - 100\)

\(\left( { - 50} \right).\left( { - 12} \right) = 600\)

\(\left( { - 18} \right).25 =  - 400\)   

\(11.\left( { - 11} \right) =  - 1111\)

$9$

$17$

$8$

$16$

\({3^8}\) 

\( - {3^7}\)   

\({3^7}\)                  

\({\left( { - 3} \right)^8}\)