ANSWER
[tex] - 7 \sqrt{6} [/tex]
EXPLANATION
The given radical expression is
[tex]3 \sqrt{6} - 10 \sqrt{2} \times \sqrt{3} [/tex]
Recall and use
[tex] \sqrt{a} \times \sqrt{b} = \sqrt{ab} [/tex]
to obtain;
[tex]3 \sqrt{6} -10 \sqrt{2 \times 3} [/tex]
Simplify the second radicand.
[tex]3 \sqrt{6} - 10 \sqrt{6} [/tex]
We have two like surds so we can simplify to obtain;
[tex] - 7 \sqrt{6} [/tex]
