Find the value of x of the area of the rectangle is 52cm. The sides lengths are 3x-5 and 4

What is the value of 1/3x + 7x when x = 5

Iwant to know what 3g+5h+4g-2h is my teacher is too selfish to tell us

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)