Question

the first and second question

Answer 1

[tex] \sqrt{31+ \sqrt{21+ \sqrt{11+x} } } =6 \\ 31+ \sqrt{21+ \sqrt{11+x} }=36 \\ \sqrt{21+ \sqrt{11+x} } =36-31 \\ 21+ \sqrt{11+x} =25 \\ \sqrt{11+x}=4 \\ 11+x=16 \\ x=5 [/tex]