5 more than twice a number is negative 13

Apple pie is removed from 350 degree oven. temperature of the pie t minutes after being removed id given by the function t(t)=72+268e-0.068t

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)

What is the simplified form of (3.25x10^3)(7.8x10^6) written in scientific notation?