Select all equations that have infinitely many solutions.

5x + 10 = 5x + 20

4(2x – 5) = 8x – 20

5x + 8 – x = 20 + 4x – 12

15x – (10 + 5x) = 20x – 10

Aladder that is 30 ft long needs to reach 27 ft up a building. what should the angle of the vertical be?

Reduce fractions expressing probability to lowest terms. in 3,000 repetitions of an experiment, a random event occurred in 500 cases. the expected probability of this event is?

Two cars which are 40 miles apart start moving simultaneously in the same direction with constant speeds. if the speed of the car which is behind is 56 mph and the speed of the other car is 48 mph, how many hours will it take for the car which is behind to catch up the car ahead of it?