Simplify: cos2x-cos4 all over sin2x + sin 4x

The sat and act tests use very different grading scales. the sat math scores follow a normal distribution with mean 518 and standard deviation of 118. the act math scores follow a normal distribution with mean 20.7 and standard deviation of 5. suppose regan scores a 754 on the math portion of the sat. how much would her sister veronica need to score on the math portion of the act to meet or beat regan's score?

∆red ≅ ∆ by rule will give brainiest if possible

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?