Let's solve the expression:

$21 + 5 \times 7 - 6$

Following the order of operations (PEMDAS: Parentheses, Exponents, Multiplication and Division, Addition and Subtraction):

1. Multiplication first: $5 \times 7 = 35$

2. Now substitute the result into the expression: $21 + 35 - 6$

3. Perform addition and subtraction from left to right: $21 + 35 = 56$ $56 - 6 = 50$

So, the final result is: $\boxed{50}$

Would you like more details or have any questions?

Here are 5 related questions to try:

1. $10 + 3 \times 8 - 4$
2. $15 - 2 \times (3 + 4)$
3. $30 + 6 \times 4 - 12$
4. $50 \div 5 + 6 \times 3$
5. $100 - 4 \times 5 + 20$

Tip: Always remember to follow the order of operations (PEMDAS) when solving expressions.