Formula Making

In the formula k=((a+b)/(a-b))^((1)/(2)) . Rewrite the formula by making 'a' the subject.

A wire of length a units is cut into two equal pieces and make a circle of radius r with one piece. Frame the formula by making r the subject.

A number x divided by 10 and 7 is added to the quotient and then the sum is multiplied by 3 to give the result N. Frame the formula by making x as the subject.

In the formula obtained in the problem 12, make the subject as p.

A is the area of the rectangle with length l units and breadth b units. Rewrite the formula for area making l as the subject.

A is the area of the square with side S units. Write the formula of area making S as the subject.