Answer:
12.124-3[tex]\sqrt{22}[/tex]
Step-by-step explanation:
[tex]\sqrt{75} = \sqrt{5^{2}*3} \\[/tex]
[tex]\sqrt{48}= \sqrt{2^{2}*2^{2}*3} \\[/tex]
[tex]\sqrt{198} =\sqrt{3^{2}*2*11} \\[/tex]
[tex]\sqrt{75} +\frac{1}{2} *\sqrt{48} - \sqrt{198} \\\\\sqrt{5^{2}*3} +\frac{1}{2} *\sqrt{2^{2}*2^{2}*3} - \sqrt{3^{2}*2*11} \\\\5\sqrt{3} +\frac{1}{2} *4 \sqrt{3} - 3 \sqrt{2*11} \\\\5\sqrt{3} +2 \sqrt{3} - 3 \sqrt{22} \\\\5*1.732 +2*1.732 - 3 \sqrt{22} \\\\8.66 + 3.464 - 3 \sqrt{22}\\\\12.124- 3 \sqrt{22}[/tex]
