Factor f(x)= 2x^4 -12x^3 +6x +20x

For one history test, keith had to answer 40 questions. of these 40 questions, keith answered 28 of them correctly. what percent did keith get on his history test? round your answer to the nearest tenth if necessary

Evaluate-27 ^4/3/8 a) - 81/16 b) 81/16 c) 16/81

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