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g/ x(x-2)-x2=5x-7
\(\Leftrightarrow x^2-2x-x^2=5x-7\\ \Leftrightarrow7x=7\Leftrightarrow x=1\)
h/\(3x\left(x-7\right)+2\left(x-7\right)=0\\ \Leftrightarrow3x^2-19x-14=0\\ \)
\(\Leftrightarrow\left(x-7\right)\left(3x+2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=7\\x=-\frac{2}{3}\end{matrix}\right.\)
Áp dụng bất đẳng thức AM-GM 3 số không âm :
\(\frac{a}{b}+\frac{b}{c}+\frac{c}{a}\ge3\sqrt[3]{\frac{abc}{abc}}=3\sqrt[3]{1}=3\)
Dấu "=" xảy ra \(\Leftrightarrow\frac{a}{b}=\frac{b}{c}=\frac{c}{a}\Leftrightarrow a=b=c\)
Áp dụng BĐT AM - GM ta có :
\(\left(1+\frac{a}{b}\right)^5+\left(1+\frac{b}{a}\right)^5\ge2^5\left(\sqrt{\frac{a}{b}}\right)^5+2^5\left(\sqrt{\frac{b}{a}}\right)^5=32\left[\left(\sqrt{\frac{a}{b}}\right)^5+\left(\sqrt{\frac{b}{a}}\right)^5\right]\)
\(\ge32.2\sqrt{\left(\sqrt{\frac{a}{b}}\right)^5\left(\sqrt{\frac{b}{a}}\right)^5}=32.2=64\)(đpcm)
Dấu "=" xảy ra \(\Leftrightarrow a=b\)
Simplifying 5(2x + 1) = 3(x + -2) Reorder the terms: 5(1 + 2x) = 3(x + -2) (1 * 5 + 2x * 5) = 3(x + -2) (5 + 10x) = 3(x + -2) Reorder the terms: 5 + 10x = 3(-2 + x) 5 + 10x = (-2 * 3 + x * 3) 5 + 10x = (-6 + 3x) Solving 5 + 10x = -6 + 3x Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-3x' to each side of the equation. 5 + 10x + -3x = -6 + 3x + -3x Combine terms: 10x + -3x = 7x 5 + 7x = -6 + 3x + -3x Combine terms: 3x + -3x = 0 5 + 7x = -6 + 0 5 + 7x = -6 Add '-5' to each side of the equation. 5 + -5 + 7x = -6 + -5 Combine terms: 5 + -5 = 0 0 + 7x = -6 + -5 7x = -6 + -5 Combine terms: -6 + -5 = -11 7x = -11 Divide each side by '7'. x = -1.571428571 Simplifying x = -1.571428571