In solving the equation 2x+5=9, which property of equality do we use first? Why?

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)

Complete the solution of the equation. find the value of y when x equals to 28 x+3y=28

Solve this problem! extra ! 3025/5.5 = a/90.75 / = fraction