Các câu hỏi tương tự
2+6+12+20+30+42=42+20+12+6+2+?
( 17/20+7/20):2=
Tính:
23 + 2 + 1 = 40 + 20 + 1 = 90 - 60 - 20 =
Tính nhẩm:
20 + 60 …
60 + 4 …
30 + 2 …
80 – 20 …
64 – 4 …
32 – 2 …
80 – 60 …
64 – 60 …
32 – 30 …
Đọc tiếp
Tính nhẩm:
| 20 + 60 = … | 60 + 4 = … | 30 + 2 = … |
| 80 – 20 = … | 64 – 4 = … | 32 – 2 = … |
| 80 – 60 = … | 64 – 60 = … | 32 – 30 = … |
20:2=?
30+20=?
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D frac{x^2-2x+2000}{x^2} 1-frac{2x}{x^2}+frac{2000}{x^2}Đặt t frac{1}{2} D 2000t2-2t+1 (20sqrt{5}t)2-2.20sqrt{5}t.frac{1}{20sqrt{5}}+left(frac{1}{20sqrt{5}}right)^2-left(frac{1}{20sqrt{5}}right)^2+1D (20sqrt{5}t-frac{1}{20sqrt{5}}) 2+frac{1999}{2000}gefrac{1999}{2000}Min D frac{1999}{2000}khi 20sqrt{5}t-frac{1}{20sqrt{5}} 0 t frac{1}{2000} frac{1}{x} frac{1}{2000} x 2000
Đọc tiếp
D= \(\frac{x^2-2x+2000}{x^2}\)= 1-\(\frac{2x}{x^2}\)+\(\frac{2000}{x^2}\)
Đặt t= \(\frac{1}{2}\)=> D= 2000t2-2t+1 = (\(20\sqrt{5}t\))2-2.\(20\sqrt{5}t\).\(\frac{1}{20\sqrt{5}}\)+\(\left(\frac{1}{20\sqrt{5}}\right)^2\)\(-\left(\frac{1}{20\sqrt{5}}\right)^2\)+1
D= (\(20\sqrt{5}t\)-\(\frac{1}{20\sqrt{5}}\)) 2+\(\frac{1999}{2000}\)\(\ge\)\(\frac{1999}{2000}\)
Min D= \(\frac{1999}{2000}\)khi \(20\sqrt{5}t\)\(-\frac{1}{20\sqrt{5}}\)= 0 => t = \(\frac{1}{2000}\)=> \(\frac{1}{x}\)= \(\frac{1}{2000}\)=> x= 2000
1 x 2 x 3 x 4 x 5 x6 x x7 x 8 x 9 x 10 x 11 x12 x 20 x 20 x182 : 19 -19 x 20 - 500 :7 = ?
6(x-2) + (-2) = 20-4x
20:2=?