22x X+X x 27 +X=25
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\(\left(x-1\right)^2+\left(x-2\right)^2=2\left(x+4\right)^2-\left(22x+27\right)\\ \Rightarrow\left(x^2-2x+1\right)+\left(x^2-4x+4\right)=2\left(x^2+8x+16\right)-\left(22x+27\right)\\ \Rightarrow x^2-2x+1+x^2-4x+4=2x^2+16x+32-22x-27\\ \Rightarrow2x^2-6x+5=2x^2-6x+5\left(luôn.đúng\right)\)
Vậy pt có vô số nghiệm
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a) (x + 2)2 - 2 (x - 3) = (x + 1)2
<=> x2 + 4x + 4 - 2x + 6 = x2 + 2x + 1
<=> x2 + 2x + 10 = x2 + 2x + 1
<=> x2 + 2x - x2 - 2x = 1 - 10
<=> 0x = -9
Vậy PT vô nghiệm
b) (x + 1)2 + (x + 2)2 = 2 (x + 4)2 - (22x + 27)
<=> (x2 + 2x + 1) + (x2 + 4x + 4) = 2 (x2 + 8x + 16) - 22x - 27
<=> x2 + 2x + 1 + x2 + 4x + 4 = 2x2 + 16x + 32 - 22x - 27
<=> 2x2 + 6x + 5 = 2x2 - 6x + 5
<=> 2x2 + 6x - 2x2 + 6x = 5 - 5
<=> 12x = 0
<=> x = 0 : 12
<=> x = 0
Vậy PT có nghiệm x = {0}
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\(\sqrt{x^2-6x+9}+\sqrt{x^2-10x+25}+\sqrt{x^2-22x+121}\)
\(=\sqrt{\left(x-3\right)^2}+\sqrt{\left(x-5\right)^2}+\sqrt{\left(x-11\right)^2}\)
\(=\left|x-3\right|+\left|x-5\right|+\left|x-11\right|\)
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3 − 2 2 x − 3 = 2 5 + 2 9 − 6 x − 3 2 3 − 2 2 x − 3 = 2 5 − 2 6 x − 9 − 3 2 3 − 2 2 x − 3 = 2 5 + 2 3 2 x − 3 − 3 2 2 3 2 x − 3 − 2 2 x − 3 = 2 5 − 3 2 − 3 2 − 6 3 2 x − 3 = 4 − 15 − 30 10 − 4 3 2 x − 3 = − 41 10 4 3 2 x − 3 = 41 10 4.10 = 41.3. 2 x − 3 40 = 123. 2 x − 3 2 x − 3 = 40 123 2 x = 40 123 + 3 2 x = 40 + 369 123 2 x = 409 123 x = 409 246
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D=5x2+5x-27x+27/(x)22(x)(2) +22
D=5x(x+1)-27(x+1)/(x-2)2
D=(5x-27)(x+1)/(x-20(x-2)
bai cua ban Hakawa Genzo sai roi -27x+27 e thanh -27(x-1) ma
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\(a.=\dfrac{2019}{2020}\times\left(\dfrac{4}{11}+\dfrac{5}{11}+\dfrac{2}{11}\right)\\ =\dfrac{2019}{2020}\times1=\dfrac{2019}{2020}\\ b.=\dfrac{25}{27}\times\left(\dfrac{17}{14}-\dfrac{1}{14}-\dfrac{2}{14}\right)\\ =\dfrac{25}{27}\times1=\dfrac{25}{27}\)
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Lời giải:
Ta có:
\(C=\frac{5(x^2-4x+4)-2x+5}{x^2-4x+4}=\frac{5(x-2)^2-2(x-2)+1}{(x-2)^2}=5-\frac{2}{x-2}+\frac{1}{(x-2)^2}\)
Đặt $\frac{1}{x-2}=t$ thì:
$C=t^2-2t+5=(t-1)^2+4\geq 4$ với mọi $t$
$\Rightarrow C_{\min}=4$. Vậy GTNN của $C$ là $4$. Giá trị này đạt tại $t=1$
$\Leftrightarrow \frac{1}{x-2}=1\Leftrightarrow x=3$
\(22\times x+27\times x+x=25\)
\(x\times\left(22+27+1\right)=25\)
\(50x=25\)
\(x=\dfrac{25}{50}=\dfrac{1}{2}\)
\(x\)x50=25
\(x\) =25:50
\(x\) =0,5