2 square roots of 7 times 2, plus the square root of 7 times 2.

Just enter this in the calculator.

$${\mathtt{2}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{7}}}}{\mathtt{\,\times\,}}{\mathtt{2}}{\mathtt{\,\small\textbf+\,}}{\sqrt{{\mathtt{7}}}}{\mathtt{\,\times\,}}{\mathtt{2}} = {\mathtt{15.874\: \!507\: \!866\: \!387\: \!543\: \!5}}$$

or

$${\mathtt{2}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{7}}}}{\mathtt{\,\times\,}}{\mathtt{2}}{\mathtt{\,\small\textbf+\,}}{\mathtt{2}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{7}}}} = {\mathtt{6}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{7}}}}$$

Please mark this post as "answer" if it helped you and solved your problem