Answer:
3x^2-x+5.2f\left(-3\right)-f\left(4\right) =
3x^2-x-19.6f
Step-by-step explanation:
3x^2-x+5.2f\left(-3\right)-f\left(4\right)
=3x^2-x-5.2f\cdot \:3-f\cdot \:4
=3x^2-x-15.6f-4f
=3x^2-x-19.6f