To simplify \( \frac{3}{7}x + \frac{2}{7}x \), you can combine the fractions since they have the same denominator:
\[ \frac{3}{7}x + \frac{2}{7}x = \frac{3 + 2}{7}x = \frac{5}{7}x \]
Therefore, the simplified expression is:
\(\frac{5}{7}x\)
So the correct response is:
Start Fraction 5 over 7 End Fraction x.