giúp mình vs ak
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13 tháng 2 2022
representatives
natural - include
recycling
mixture
environmentally
packaging
2 tháng 7 2021
Bài 5:
a) Ta có: \(A=\left(\dfrac{4x+5\sqrt{x}-1}{x\sqrt{x}+2x-\sqrt{x}-2}-\dfrac{3\sqrt{x}+1}{x+\sqrt{x}-2}\right):\dfrac{x+4\sqrt{x}+4}{x-1}\)
\(=\left(\dfrac{4x+5\sqrt{x}-1}{\left(\sqrt{x}+2\right)\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}-\dfrac{\left(3\sqrt{x}+1\right)\left(\sqrt{x}+1\right)}{\left(\sqrt{x}+2\right)\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\right):\dfrac{\left(\sqrt{x}+2\right)^2}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\)
\(=\dfrac{4x+5\sqrt{x}-1-3x-3\sqrt{x}-\sqrt{x}-1}{\left(\sqrt{x}+2\right)\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\cdot\dfrac{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}{\left(\sqrt{x}+2\right)^2}\)
\(=\dfrac{x+\sqrt{x}-2}{\left(\sqrt{x}+2\right)^3}\)
\(=\dfrac{\sqrt{x}-1}{x+4\sqrt{x}+4}\)
b) Ta có: \(A-1=\dfrac{\sqrt{x}-1-x-4\sqrt{x}-4}{x+4\sqrt{x}+4}\)
\(=\dfrac{-\left(x+3\sqrt{x}+5\right)}{x+4\sqrt{x}+4}\)
\(=\dfrac{-\left(x+2\cdot\sqrt{x}\cdot\dfrac{3}{2}+\dfrac{9}{4}\right)-\dfrac{11}{4}}{x+4\sqrt{x}+4}< 0\forall x\) thỏa mãn ĐKXĐ
nên A<1
18 tháng 10 2021
1: Ta có: \(\sqrt{x^2+3x+2}=1\)
\(\Leftrightarrow x^2+3x+2=1\)
\(\Leftrightarrow x^2+3x+1=0\)
\(\text{Δ}=3^2-4\cdot1\cdot1=5\)
Vì Δ>0 nên phương trình có hai nghiệm phân biệt là:
\(\left\{{}\begin{matrix}x_1=\dfrac{-3-\sqrt{5}}{2}\\x_2=\dfrac{-3+\sqrt{5}}{2}\end{matrix}\right.\)
1 will have
2 looked
3 would understand
4 would arrive
5 swim
6 press
7 would call-were
8 listened
9 won't dry out
10 gave
11 won't find
12 would visit
1 will have
2 looked
3 would understand
4 would arrive
5 swim
6 press
7 would call-were
8 listened
9 won't dry out
10 gave
11 won't find
12 would visit