一個(gè)三位數(shù)的三個(gè)數(shù)字的和是17,百位數(shù)字與十位數(shù)字的和比個(gè)位數(shù)字大3,如果把個(gè)位數(shù)字與百位數(shù)字的位置對(duì)調(diào),那么所得的三位數(shù)比原數(shù)大495,求原來的三位數(shù).
設(shè)原來的三位數(shù)的百位數(shù)字為x、十位數(shù)字為y、個(gè)位數(shù)字為z,根據(jù)題意,得
| x+y+z=17 | x+y?z=3 | (100z+10y+x)?(100x+10y+z)=495. |
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解得:
故原來的三位數(shù)是287.