Sarah has grades of 98 and 98 on her first two test if she want to average at least 80 after her third test what must she make on that test

Which has the greater energy, light of wavelength 519 nm or light with a frequency of 5.42 x 10^8 sec^-1?

In the next 10 month,colin wants to save $900 for his vacation.he plans to save $75 each of the first 8 months. how much must he save each of the last 2 months in order to meet his goal if he saves the same amount each month ?

Can someone me on this math worksheet about finding the given variable for these angles, and whether the triangles are similar. i really need these answers i’m so confused: ( !