If i = prt, which equation is equivalent to t?

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)

For each proportion find the unknown number x 1/5/8=×/15

Which shows the correct substitution of the values a,b and c from the equation 1=-2x+3x^2+1