[tex]\left(\sqrt[3]{- \dfrac 18} \right)^3+3\dfrac3 4\\\\\\=\left[\left(-\dfrac 18 \right)^{\tfrac 13}\right]^3+ \dfrac{12+3}4\\\\\\=\left(-\dfrac 18 \right)^{\tfrac 33\right)+ \dfrac{15}4\\\\\\=\dfrac{15}{4}- \dfrac 18\\\\\\\\=\dfrac{30-1}{8}\\\\\\=\dfrac{29}8\\\\\\=3\dfrac 58 \\\\\\= 3.625[/tex]
