f5數學顯兩條?20點

2011-01-07 3:22 am

1.by substituting(x^2+5x+!)^1/2=u,show 3x^2+15x+2(x^2+5x+1)^1/2can be reduced to 3u^2+2u-3
2.show that x^2+x+2x(x=2)^1/2=14

更新1:

sorry!should be2.show that x^2+x+2x(x=2)^1/2=(x+(x+2)^2)^2-2

更新2:

sorry!should be2.(x+(x+2)^(1/2))^2-2

更新3:

should be2.show that x^2+x+2x(x=2)^1/2=(x+(x+2)^2)^2-2

更新4:

sorry!these three delete should be2.show that x^2+x+2x(x=2)^1/2=(x+(x+2)^(1/2))^2-2

回答 (1)

2011-01-07 4:29 am

✔ 最佳答案

As follows:

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2011-01-06 22:19:13 補充：
Is that (x+(x+2)^(1/2))^2-2?? If so, I have done it.

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