Let's convert the units first.
1.08 kg * (1000 g)/(1 kg) = 1008 g
density = mass/volume
density = 1008 g / 400 cm^3
density = 2.52 g/cm^3
Answer: 2.52 g/cm^3
First distribute the negative
(-x+2)(x-7)
Next multiply -x by x
Then multiply 2 by x
Then multiply -x by -7
Then multiply 2 by -7
-x^2+2x+7x-14
-x^2+9x-14 is your answer
The answer is B hope this would help you