The problem asks to simplify expressions involving multiplication of exponents with the same base. The rule to use is $a^m \cdot a^n = a^{m+n}$. We need to apply this rule to each problem.

1. Problem Description

The problem asks to simplify expressions involving multiplication of exponents with the same base. The rule to use is $a^m \cdot a^n = a^{m+n}$. We need to apply this rule to each problem.

2. Solution Steps

1. $7^4 \cdot 7^7 = 7^{4+7} = 7^{11}$

2. $9^6 \cdot 9^8 = 9^{6+8} = 9^{14}$

3. $2^7 \cdot 2^4 = 2^{7+4} = 2^{11}$

4. $5^6 \cdot 5^8 = 5^{6+8} = 5^{14}$

5. $7^9 \cdot 7^3 = 7^{9+3} = 7^{12}$

6. $4^7 \cdot 4^2 = 4^{7+2} = 4^9$

7. $5^8 \cdot 5^7 = 5^{8+7} = 5^{15}$

8. $4^2 \cdot 4^5 = 4^{2+5} = 4^7$

9. $9^8 \cdot 9^3 = 9^{8+3} = 9^{11}$

1

0. $5^8 \cdot 5^6 = 5^{8+6} = 5^{14}$

3. Final Answer

1. $7^{11}$

2. $9^{14}$

3. $2^{11}$

4. $5^{14}$

5. $7^{12}$

6. $4^9$

7. $5^{15}$

8. $4^7$

9. $9^{11}$

1

0. $5^{14}$