118×122
=(120-2)×(120+2)
=120²-2²
=14400-4
=14396
2055²-2066×2004
=2055²-(2035+31)×(2035-31)
=2055²-(2035²-31²)
=2055²-2035²+31²
=(2055²-2035²)+31²
=(2055+2035)×(2055-2035)+(30+1)²
=4090×20+30²+2×20×1+1²
=4090×20+900+40+1
=8180+900+40+1
=9080+40+1
=9120+1
=9121
剩下的,大同小异,楼主参照我给出的答案,自己做个练习吧