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which description represents the expression 4−x3 ?

4 times the quotient of a number and 3
4 minus the quotient of a number and 3
4 added to the product of a number and 3
4 minus a number times 3

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)