What is the value of x if (3x+1)/(5) - 2 = 6?

Undo the operations in reverse order. Add 2 to both sides of $\frac{3x + 1}{5} - 2 = 6$ to get $\frac{3x + 1}{5} = 8$. Multiply by 5: $3x + 1 = 40$. Subtract 1: $3x = 39$. Divide by 3: $x = 13$, choice D. Check: $\frac{3(13) + 1}{5} - 2 = 8 - 2 = 6$. Choice A (11) gives $\frac{34}{5} - 2 = 4.8$, choice B (15) gives $\frac{46}{5} - 2 = 7.2$, and choice C (9) gives $\frac{28}{5} - 2 = 3.6$; none equals 6. Typical errors are subtracting 2 instead of adding it, or forgetting to multiply the 2 by 5.