" 7."y=4x-x^(2),quad y=5-2x

If P=7x^2+5x y-9y^2,\ Q=4y^2-3x^2-6x y and R=-4x^2+x y+5y^2, show that P+Q+R=0.

If P=7x^2+5x y-9y^2,\ Q=4y^2-3x^2-6x y and R=-4x^2+x y+5y^2, show that P+Q+R=0.

Classify the following pairs of lines as coincident, parallel, perpendicular or intersecting : (i) 6x+14y-16=0 , 12x+28y-32=0 (ii) 3x-4y=8 , 3x+4y=11 (iii) 5x-2y=7 , 2y-5x=-7 (iv) 4x+7y=19 , 7x-4y=-2 (v) x-2y=7 , 4y-2x=13

The equation to a pair of opposite sides of a parallelogram are x^2-5x+6=0 and y^2-6y+5=0 . The equations to its diagonals are x+4y=13 ,y=4x-7 (b) 4x+y=13 ,4y=x-7 4x+y=13 ,y=4x-7 (d) y-4x=13 ,y+4x-7

The equation to a pair of opposite sides of a parallelogram are x^2-5x+6=0 and y^2-6y+5=0 . The equations to its diagonals are x+4y=13 ,y=4x-7 (b) 4x+y=13 ,4y=x-7 4x+y=13 ,y=4x-7 (d) y-4x=13 ,y+4x-7

The equation to a pair of opposite sides of a parallelogram are x^2-5x+6=0 and y^2-6y+5=0 . The equations to its diagonals are x+4y=13 ,y=4x-7 (b) 4x+y=13 ,4y=x-7 4x+y=13 ,y=4x-7 (d) y-4x=13 ,y+4x-7

The equation to a pair of opposite sides of a parallelogram are x^2-5x+6=0 and y^2-6y+5=0 . The equations to its diagonals are (a) x+4y=13 ,y=4x-7 (b) 4x+y=13 ,4y=x-7 (c) 4x+y=13 ,y=4x-7 (d) y-4x=13 ,y+4x-7

Add the algebraic expressions: 4x y^2-7x^2y ,\ 12 x^2y-6x y^2,\ -3x^2y+5x y^2

Solve the following system of equations by matrix method : 5x+7y+2=0 4x+6y+3=0 5x+2y=3 3x+2y=5 3x+4y-5=0 x-y+3=0 3x+y=19 3x-y=23 3x+7y=4 x+2y=-1 3x+y=7 5x+3y=12