Given the function f(x)=x, how does the addition or subtraction of a constant to the output affect the graph? f(x)=x-2

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

Which of the following parabolas opens down?

Prove that 16^4-2^13-4^5 is divisible by 11.