The missing exponent is -3. The exponent on the x variable only applies to x, so with that in mind, only x is in the denominator. This means that its exponent needs to be a negative. A negative exponent flips its base to the reciprocal making x into 1/x. When multiplying only an exponent, you multiply the two exponents. For example: (y^4)^2 = y^8. 2 times 3 is 6.
The missing exponent is -3. A negative exponent flips the base to its reciprocal making 2x/3 into 3/2x, and 3^3 is 27. The same applies to 2x. (2x)^3 is 8x^3.
The other one’s missing exponent is 2. As, mention before, a negative exponent results in flipping the base to its reciprocal making 1/3 into 3. 3^3 is 27. You can figure out which exponent make 3 into 9 which is 2.
Hope this helped.