1. **Problem:** Calculate the value of expression a) from Bài 8: $$2^3 - \frac{5^3}{5^2} + 12 \cdot 2^2$$ 2. **Formula and rules:** - Use exponentiation rules: $$a^m \div a^n = a^{m-n}$$ - Follow order of operations: parentheses, exponents, multiplication/division, addition/subtraction. 3. **Step-by-step solution:** - Calculate powers: $$2^3 = 8$$ $$5^3 = 125$$ $$5^2 = 25$$ $$2^2 = 4$$ - Simplify division: $$\frac{5^3}{5^2} = \frac{125}{25} = 5$$ - Multiply: $$12 \cdot 4 = 48$$ - Substitute back: $$8 - 5 + 48$$ - Perform addition and subtraction: $$8 - 5 = 3$$ $$3 + 48 = 51$$ 4. **Final answer:** $$\boxed{51}$$