In which year was the Social Identity Theory first proposed?

Write the following statement in the form of equation. If you take 9 from 5 times x, then you get 85-

What is the simplified value of $\frac{(2.7{)}^3+(1.3{)}^3}{(2.7{)}^2-2.7\times 1.3+(1.3{)}^2}?$

If $a+b+c=13$ and $ab+bc+ca=54$, then $a^3+b^3+c^3-3abc$ is equal to:

Which of the following statements about 'Barnaparichay', a mid ${19}^{\mathrm{th}}$ century Bengali text, is/are correct?
$1.$ It was written by Raja Ram Mohan Roy.
$2.$ It was the most widely used Bengali primer of the time.

Select the correct answer using the code given below.

Expand : ${\left(\mathrm{W}-9\right)}^2$

1. $\left({\mathrm{W}}^2-9\mathrm{W}+81\right)$

2. $\left({\mathrm{w}}^2-9\mathrm{W}+18\right)$

3. $\left({\mathrm{W}}^2-18\mathrm{W}+81\right)$

4. $\left({\mathrm{W}}^2-18\mathrm{W}-81\right)$

Simplify $\frac{81x^2-49y^2}{9x+7y}$