Can someone pls help me

He mass of a single atom of carbon can be found by dividing the atomic mass (12.01 g) by 6.022 x 10^23. which is the mass of a single carbon atom, correctly written in scientific notation with the correct number of significant figures?

Julie was able to walk 16 km through the zoo in 6 hours. how long will it take her to walk 24 km through the zoo?

20 points plus brainliest andwer plus my hover hoard im v desperate ! evaluate the polynomial for x=-2 in the equation -3x^3+7x^2-7x-1 (simplify your answer)