What is 4x squares minus 81

Consider the function y = f(x)=3^x the values of f(1/2) and f(1/4). rounded to the nearest hundredth, are__and__ respectively

Bocephus has a bag full of nickels and dimes. if there are 3 times as many dimes as nickels, and he has $\$36.05$ in his bag, how many nickels does he have?

Atest consists of 10 multiple choice questions, each with 5 possible answers, one of which is correct. to pass the test a student must get 60% or better on the test. if a student randomly guesses, what is the probability that the student will pass the test?