34+34x99=34x1+34x99=34x（1+99）=34x100=3400
35x35+35x64+35=35x35+35x36+35x1=35x（36+35+1）=35x72=2520
173x73-73x73=73x（173-73）=73x100=7300
98x37=37x（100-2）=3700-74=3626
99x49+49=49x（99+1）=49x100=4900
125x9-125=125x（9-1）=125x8=1000