Let's express the following expressions as the sum of two squares.

$2(a^2+b^2)$

Let's express the following expressions as the sum of two squares.

$50x^2+18y^2$

Let's express the following expressions as the sum of two squares.

$a^2+b^2+c^2+d^2+2(ac-bd)$

Write for which value of $t$, $x^2-tx+\frac{1}{4}$ will be whole square form.

Write the expression which when added to $a^2+4$ gives a whole number.

If $a \& b$ positive integers and $a^2-b^2=9\times 11$, write the value of $a \& b$

${\left(x+y\right)}^2-{\left(x-y\right)}^2=4xy$ an identity or an equation? Write  with reason.

For each positive or negative value of $x$ and $y$ except zero the value of $x^2+y^2$ is always_____

Find the value of $x$: 

$6x=72$