Đáp án:
\(\dfrac{{77}}{8}\)
Giải thích các bước giải:
\(\begin{array}{l}
f\left( { - 1} \right) = 2.{\left( { - 1} \right)^2} - 3.{\left( { - 1} \right)^3} - 1 + 1\\
= 2 + 3 = 5\\
\to 2f\left( { - 1} \right) = 10\\
h\left( { - \dfrac{1}{2}} \right) = 2.{\left( { - \dfrac{1}{2}} \right)^2} + 1 = \dfrac{3}{2}\\
\to - \dfrac{1}{4}h\left( { - \dfrac{1}{2}} \right) = - \dfrac{1}{4}.\dfrac{3}{2} = - \dfrac{3}{8}\\
2f\left( { - 1} \right) - \dfrac{1}{4}h\left( { - \dfrac{1}{2}} \right) = 10 - \dfrac{3}{8} = \dfrac{{77}}{8}
\end{array}\)
