21*(2/7)^2+2/7

To simplify the expression \( 21 \left( \frac{2}{7} \right)^2 + \frac{2}{7} \), let's break it down step-by-step.

1. First, calculate \( \left( \frac{2}{7} \right)^2 \): \[ \left( \frac{2}{7} \right)^2 = \frac{2^2}{7^2} = \frac{4}{49} \]

2. Now, multiply this result by 21: \[ 21 \cdot \frac{4}{49} = \frac{21 \cdot 4}{49} = \frac{84}{49} \]

3. Simplify \( \frac{84}{49} \): \[ \frac{84}{49} = \frac{84 \div 7}{49 \div 7} = \frac{12}{7} \]

4. Now add \( \frac{2}{7} \) to \( \frac{12}{7} \): \[ \frac{12}{7} + \frac{2}{7} = \frac{12 + 2}{7} = \frac{14}{7} \]

5. Simplify \( \frac{14}{7} \): \[ \frac{14}{7} = 2 \]

So, the final result of the expression \( 21 \left( \frac{2}{7} \right)^2 + \frac{2}{7} \) is \( \boxed{2} \).