两道七年级数学题
(1)[(x^2+18x+72)除以(x+12)-(x^2+5x-6)除以(x-1)]×(x^3-2x^2-x+1)(2)5.81×10^12-5×10^10------...
(1)[(x^2+18x+72)除以(x+12)-(x^2+5x-6)除以(x-1)]×(x^3-2x^2-x+1)
(2)5.81×10^12-5×10^10
----------------------------------------(此乃分数线。也可看成上面的除以下面的)
(-1.25×10^4)×(1.6×10^6) 展开
(2)5.81×10^12-5×10^10
----------------------------------------(此乃分数线。也可看成上面的除以下面的)
(-1.25×10^4)×(1.6×10^6) 展开
1个回答
展开全部
①
[(x²+18x+72)÷(x+12)-(x²+5x-6)÷(x-1)]×(x³-2x²-x+1)
=[(x+6)(x+12)÷(x+12)-(x+6)(x-1)÷(x-1)]×(x³-2x²-x+1)
=[(x+6)-(x+6)]×(x³-2x²-x+1)
=0
②
5.81×10^12-5×10^10
---------------------------
(-1.25×10^4)×(1.6×10^6)
=-10^10×(581-5)÷[(10^4×10^6)×(1.25×0.8×2)]
=-576÷2
=-288
[(x²+18x+72)÷(x+12)-(x²+5x-6)÷(x-1)]×(x³-2x²-x+1)
=[(x+6)(x+12)÷(x+12)-(x+6)(x-1)÷(x-1)]×(x³-2x²-x+1)
=[(x+6)-(x+6)]×(x³-2x²-x+1)
=0
②
5.81×10^12-5×10^10
---------------------------
(-1.25×10^4)×(1.6×10^6)
=-10^10×(581-5)÷[(10^4×10^6)×(1.25×0.8×2)]
=-576÷2
=-288
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询