In a code language $3690$ means 'you will help me'; $1369$ means 'I will help you'; $12469$ means 'why I will help them' and $748$ means 'kill them doctor'. On the basis of the above information the code for which of the following can't be obtained with certainty?

What should come in place of the question mark (?) in the following question?

$(11{)}^{2 }+ (9{)}^2 - (14{)}^2 +? = 3^2$

What should come in place of the question mark (?) in the following question?

$0.5\times 3.9 ÷ 1.3 = ? + 0.5$

What should come in place of the question mark (?) in the following question?

$\frac{15}{31}÷\frac{90}{186}\times \frac{729}{9}={\left(?\right)}^2$

What should come in place of the question mark (?) in the following question?

$81\% of 2300 - 34\% of 596 =?$

What should come in place of the question mark?

$3.1\times 2.6\times 1.5=?$

What should come in place of the question mark (?) in the following question?

$\left(\frac{144}{16} \times \frac{828}{9}\right) = ? + 325$