Add the following expressions.
`x - 2y, 3x + 4y`

Factorise the following expression : (x + y)^2 - 4xy .

Factorise the following expression - (x - y)^(2) +4xy (Hint : first expand (x -y)^(2) )

If x = 1 , y = 2 find the values of the following expressions: 4x- 6y +5

Add the following terms: x-2y , 3x+4y

Find the equation of the radical axis of the following circles. x^2 + y^2 - 3x - 4y + 5 = 0. 3(x^2 + y^2) - 7x + 8y - 11 = 0

Find three different solutions of the each of the following equations. (i) 3x + 4y = 7 (ii) y = 6x (iii) 2x - y = 7 (iv) 13x - 12y = 25 (v) 10x + 11y = 21 (vi) x + y = 0

Solve the following systems of equations: x-2y=0, 3x+4y=20.

Find the equation of the common chord of the following pair of circles. x^2 + y^2 - 4y + 3 = 0 , x^2 + y^2 - 5x - 6y + 4 = 0 .

Express each of the following equations in the form of ax + by + c = 0 and write the values of a, b and c. (i) 3x + 4y = 5 (ii) x - 5 = sqrt3y (iii) 3x = y (iv) x/2+y/2=1/6 (v) 3x - 7 = 0