[tex]\qquad\qquad\huge\underline{{\sf Answer}}♫[/tex]
Let's solve ~
[tex]\qquad \sf \dashrightarrow \: \frac{1}{2} (5 + 13) - 4.5[/tex]
[tex]\qquad \sf \dashrightarrow \: \frac{1}{2} (18) - 4.5[/tex]
[tex]\qquad \sf \dashrightarrow \: 9 - 4.5[/tex]
[tex]\qquad \sf \dashrightarrow \:4.5[/tex]
[tex]\qquad \sf \dashrightarrow \:(5 + 11) - (24 - 15) \times 3[/tex]
[tex]\qquad \sf \dashrightarrow \:16 - (9 \times 3)[/tex]
[tex]\qquad \sf \dashrightarrow \:16 - 27[/tex]
[tex]\qquad \sf \dashrightarrow \: - 11[/tex]
[tex]\qquad \sf \dashrightarrow \: {6}^{2} + (3 \times 7) - (9 \div 3)[/tex]
[tex]\qquad \sf \dashrightarrow \:36 + 21 - 3[/tex]
[tex]\qquad \sf \dashrightarrow \:57 - 3[/tex]
[tex]\qquad \sf \dashrightarrow \:54[/tex]