The expression "1^4 x 1^?" is equal to "1^12", so we can write:
1^4 * 1^? = 1^12
Using the exponent rule that a^m * a^n = a^(m + n), we can simplify this equation as follows:
1^(4 + ?) = 1^12
Since the base of the exponents is 1, the value of the exponent is the same as the exponent of the result:
4 + ? = 12
Solving for the unknown exponent, we can subtract 4 from both sides:
? = 12 - 4
? = 8
So, the value of '?' is 8.