Answer :

To evaluate the expression [tex]\( 3 \cdot (5 + 4)^2 - 4^2 \)[/tex] step-by-step, follow these instructions:

1. Calculate inside the parentheses:
[tex]\[ 5 + 4 = 9 \][/tex]

2. Square the result from the parentheses:
[tex]\[ 9^2 = 81 \][/tex]

3. Multiply by 3:
[tex]\[ 3 \cdot 81 = 243 \][/tex]

4. Calculate [tex]\( 4^2 \)[/tex]:
[tex]\[ 4^2 = 16 \][/tex]

5. Subtract the result of the square of 4 from the multiplied result:
[tex]\[ 243 - 16 = 227 \][/tex]

So, the evaluated expression is:
[tex]\[ 3 \cdot (5 + 4)^2 - 4^2 = 227 \][/tex]