To solve the equation \( \frac{2}{3}x + 6 = 21 \), follow these steps:
- Subtract 6 from both sides:
\[ \frac{2}{3}x = 21 - 6 \]
\[ \frac{2}{3}x = 15 \]
- Multiply both sides by the reciprocal of \( \frac{2}{3} \), which is \( \frac{3}{2} \):
\[ x = 15 \times \frac{3}{2} \]
- Calculate the right side:
\[ x = \frac{15 \times 3}{2} = \frac{45}{2} \]
- Simplify:
\[ x = 22.5 \]
Thus, the solution is
\[ x = 22.5 \]