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

$$ \sqrt{0.00004761} $$   equal to

Simplify the following equation
$$ {\sqrt{(1-sin^{2}θ) ÷{(1-cos^{2}θ)}}}$$

Simplify : $$ {(7) ^{2} ÷(7^{1\over 2})^{4}}$$

Solve: 12–[26–{2+5×(6–3)}]

25.6% of 250 +√ ? = 119

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

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

Direction : What should come in place of the question (?) in the following question.

$$ {\sqrt{441}}+ {(71)^{2}} -{(?)^{2}}=2707 $$