What expression makes the equation true?

To get this answer, you multiply the coefficients 9 and -2 to get 9*(-2) = -18. This is the coefficient of the answer. Also, you add the exponents 9 and -3 to get 9+(-3) = 6. This is the exponent of the answer. We are only able to add the exponents since the bases are both the same (both 10).

its c or d   take a lucky guess my dude