计算:x+(x+y)+(x+2y)+···+(x+99y)等于?
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计算:x+(x+y)+(x+2y)+···+(x+99y)等于?
计算:x+(x+y)+(x+2y)+···+(x+99y)等于?
计算:x+(x+y)+(x+2y)+···+(x+99y)等于?
x+(x+y)+(x+2y)+···+(x+99y)
= (x+x+x+...(共100个x)) + (y+2y+3y+...+99y)
= 100x + (1+99)/2*99y
= 100x + 4950y
100x+4950y
x+(x+y)+(x+2y)+···+(x+99y)
=100x+y+2y+99y
=100x+00(99+1)/2y
=100x+4950y
x+(x+y)+(x+2y)+···+(x+99y)
=x×100+(y+2y+……+99y)
=100x+(1+99)×99/2×y
=100x+4950y请问 y+2y+3y 。。。到99Y 是怎么算的 ??y+2y+……+99y=(1+2+3……+99)y (1+99)+(2+98)+(3+97)+……+(49+51...
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x+(x+y)+(x+2y)+···+(x+99y)
=x×100+(y+2y+……+99y)
=100x+(1+99)×99/2×y
=100x+4950y
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x+(x+y)+(x+2y)+···+(x+99y)
=100x+(y+2y+3y+...+99y)
=100x+(1+99)*99y/2
=100x+4950y