Deborah has 13 five and ten dollar bills in her wallet she has a total of $90. how many five dollar bills does she have? how many 10 dollar bills does she have?

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning

Which representation has a constant of variation of -2.5

Geometry in the diagram, ∠abc is a right angle. ∠dbc = 30°27'40". find the measure of ∠abd.