Vi (-10)^8 co dang
100....0
=> 10...0+8=> 100...8
De tong tren : 9
=> 1+0+0+0+..+8=9
=> 10...8:9
=> (-10)^8+2^3:9
a=\(\left(-10\right)^8+2^3\)=100000008
mà 100000008 chia hết cho -9
=> a cũng chia hết cho -9
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