找规律并将式子化简(a+b)+(2a+1/2b)+(3a+1/2×3b).(99+1/98×99b)再代入a=2b=－99

找规律并将式子化简(a+b)+(2a+1/2b)+(3a+1/2×3b).(99+1/98×99b)再代入a=2b=－99
找规律并将式子化简(a+b)+(2a+1/2b)+(3a+1/2×3b).(99+1/98×99b)再代入a=2
b=－99

找规律并将式子化简(a+b)+(2a+1/2b)+(3a+1/2×3b).(99+1/98×99b)再代入a=2b=－99
(a+b)+(2a+1/2b)+(3a+1/2×3b).(99a+1/98×99b)
=a+2a+3a+.+99a+b+1/2b+1/2*3b+.+1/98*99b
=(a+99a)*99/2+b(1+1/1*2+1/2*3+.+1/98*99)
=50a*99+b(1+1-1/2+1/2-1/3+.+1/98-1/99)
=4950a+b(2-1/99)
=4950a+197b/99
=4950*2+197/99*(-99)
=9900-197
=9703

楼下的大侠是对的

原式=(a+2a+3a+......+99a)+(b+1/2b+1/2×3+1/3×4+......+1/98×99)b
=(1+2+3+......99)a+(1+1/2+1/2×3+......+1/98×99)b
=(1+99)×99÷2×a+[1+(1-1/2)+(1/2-1/3)+(1/3-1/4)+......+(1/98-1/99)]b

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原式=(a+2a+3a+......+99a)+(b+1/2b+1/2×3+1/3×4+......+1/98×99)b
=(1+2+3+......99)a+(1+1/2+1/2×3+......+1/98×99)b
=(1+99)×99÷2×a+[1+(1-1/2)+(1/2-1/3)+(1/3-1/4)+......+(1/98-1/99)]b
=4950a+(1+1-1/2+1/2-1/3+1/3-1/4+......+1/98-1/99)b
=4950a+197/99b
当a=2,b=-99时
原式=4950×2-197
=9703

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