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So sánh nha!!!
\(A=\left(1+2+3+4+5\right)^2=15^2=225\)
\(B=\left(1^3+2^3+3^3+4^3+5^3\right)\\ =\left(1+8+27+64+125\right)=225\)
Vì: 225=225
=> \(A=B\)
A=(1+2+3+4+5)2=152=225
B=(13+23+33+43+53)= 1+8+9+64+125=225
Vì 225=225
Nên A=B
1. Tìm GTNN
a) \(B=\left|3x+5\right|\)
\(\Rightarrow B=\left|3x+5\right|\ge0\)
Vậy GTNN của \(B=\left|3x+5\right|\)\(=0\) khi x=\(\dfrac{-5}{3}\)
b) \(C=4.\left|3+2x\right|+1\)
\(\Rightarrow\)\(C=4.\left|3+2x\right|+1\)\(\ge1\)
Vậy GTNN của \(C=4.\left|3+2x\right|+1\)\(=1\) khi x=\(\dfrac{-3}{2}\)
\(B=\left|3x+5\right|\)
\(\left|3x+5\right|\ge0\)
\(B_{MIN}\)
\(\Rightarrow B_{MIN}=0\)khi \(\left|3x+5\right|=0\)
\(C=4\left|3+2x\right|+1\)
\(\left|3+2x\right|\ge0\Rightarrow4\left|3+2x\right|\ge0\)
\(C_{MIN}\Rightarrow\left|3+2x\right|=0\Rightarrow4\left|3+2x\right|=0\)
\(C_{MIN}=0+1=1\)
\(C_{MIN}=1\)khi \(4\left|3+2x\right|=0\)
a)\(\dfrac{-1}{3}+\dfrac{2}{1}-\dfrac{6}{5}=\dfrac{-5}{15}+\dfrac{30}{15}-\dfrac{18}{15}=\dfrac{7}{15}\)
dai dong qua(de)
\(4x\cdot\left(x:2\right)-3\left(1-2x\right)=7-2\left(x+1\right)\)
\(\Leftrightarrow4x\cdot\dfrac{x}{2}-3+6x=7-2x-2\)
\(\Leftrightarrow2x\cdot x-3+6x=5-2x\)
\(\Leftrightarrow2x^2-3+6x=5-2x\)
\(\Leftrightarrow2x^2-3+6x-5+2x=0\)
\(\Leftrightarrow2x^2-8+8x=0\)
\(\Leftrightarrow2\left(x^2-4+4x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-2+2\sqrt{2}\\x=-2-2\sqrt{2}\end{matrix}\right.\)
Vậy \(x_1=-2-2\sqrt{2};x_2=-2+2\sqrt{2}\)
\(4x\left(x:2\right)-3x\left(1-2x\right)=7-2\left(x+1\right)\)
\(\Leftrightarrow4x.\dfrac{x}{2}-3+6x-7+2x+2=0\Leftrightarrow2x^2+8x-8=0\Leftrightarrow2\left(x^2+4x-4\right)=0\)
\(\Leftrightarrow\left(x^2+4x+4\right)-8=0\)
\(\Leftrightarrow\left(x+2\right)^2=8\Rightarrow\left[{}\begin{matrix}x-2=\sqrt{8}\\x-2=-\sqrt{8}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\sqrt{2}+2\\x=-\sqrt{8}+2\end{matrix}\right.\)
a)\(\dfrac{-1}{4}\cdot13\dfrac{9}{11}-0,25\cdot6\dfrac{2}{11}\)
\(=\dfrac{-1}{4}\cdot\dfrac{152}{11}-\dfrac{1}{4}\cdot\dfrac{68}{11}\)
=\(\dfrac{1}{4}\cdot\left(\dfrac{-152}{11}-\dfrac{68}{11}\right)\)
\(=\dfrac{1}{4}\cdot\dfrac{-220}{11}=-5\)
b,(-1)2017 -(-8)2+73:72
=(-1)-64+7
=-65+7
= -58
a) \(\dfrac{\left(3\times4\times2^{16}\right)^2}{\left(11\times2^{13}\times4^{11}\right)}\) = \(\dfrac{3^2\times2^4\times2^{32}}{11\times2^{13}\times2^{22}}\) = \(\dfrac{9\times2^{36}}{11\times2^{35}}\) = \(\dfrac{9\times2}{11}\) = \(\dfrac{18}{11}\)
b) \(\left(-1\right)^{2017}-\left(-8\right)^2+7^3:7^2\) = \(-1-64+7\) = \(-58\)