Which equation has x is equal to 4 as the solution?

Substitute x = 4 into choice B: 3(4) + 4 = 16, and log base 4 of 16 equals 2 because 4² = 16. So choice B has x = 4 as a solution. The other choices do not: their logarithms evaluate to 3, 1, and 2, respectively, rather than 4, 2, and 2 as required.

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