Solve the following systems of equations without graphing 5x + 10y = 30

Including 6% sales tax, an inn charges $135.68 per night. find the inns nightly cost

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap

Perry observes the opposite parallel walls of a room in how many lines do the plains containing the walls intersect