Help soon please! I need to get done soon

The sum of the reciprocal of a positive number and the reciprocal of 2 more than the number is 3/4 equation: the number is

If the speed of an electromagnetic wave is 100,000 cm/s and its wavelength is 100 cm, what is its frequency? a) 100,000 cycles per second (hz) b) 1 × 10-3 cycles per second (hz) c) 10,000,000 cycles per second (hz) d) 1,000 cycles per second (hz)

Julius sold five times as many computers as sam sold last year. in total, they sold 78 computers. how many computers did julius sell?