75=n+12 what is the full problem and check your answers with simplifacation

Will give brainliest what is the value of x? enter your answer in the box.

Afarm that has 4 x 10^2 acres has 1.2 x 10^5 cattle. what is the average number of cattle per acre? write the answer in scientific notation. answere asap

Roger could feed 5 walruses with 4 kilograms of fish. how many walruses could he feed with 7.2 kilograms of fish?