\(A=\dfrac{1}{2}\cdot\dfrac{30\left|x+1\right|+64}{6\left|x+1\right|+8}\)
\(=\dfrac{1}{2}\cdot\dfrac{30\left|x+1\right|+40+24}{6\left|x+1\right|+8}=\dfrac{1}{2}\cdot5\cdot\left(\dfrac{12}{6\left|x+1\right|+8}\right)\)
\(=\dfrac{5}{2}\cdot\dfrac{6}{3\left|x+1\right|+4}< =\dfrac{5}{2}\cdot\dfrac{6}{3+4}=\dfrac{5}{2}\cdot\dfrac{6}{7}=\dfrac{30}{14}=\dfrac{15}{7}\)
Dấu = xảy ra khi x=-1