Direction: what should come in place at question mark(?).

$$ {\sqrt{4489}+(71)^{2}-(?)^{2}=2707}$$

Simplify the following expression.

 25-(4÷2)+11.5+9.5

Evaluate: $${-(4-6)^2-3(-2)+।-6।\over 18-9÷3×5}$$

The value of $$ {\sqrt{0.6912}+{\sqrt{0.5292}}\over {\sqrt{0.6912}-{\sqrt{0.5292}}}}$$ is:

If $${a+b=10}$$ and $$ \sqrt{a\over b}-13=-\sqrt{b\over a}-11$$, then what is the value of $${3ab+4a^2+5b^2}$$?

Simplify : $$ {5\over3}×{7\over51}\ of \ {17\over5}-{1\over3}\over {2\over9}×{5\over7}\ of \ {28\over5}-{2\over3}  $$

Find the value of $$ {5^{1\over2}-[3^{1\over4}+6-4÷2]}$$

What is the value of $$ {0.55 × 4.5\over 0.81}$$ ?