4x^(2)+8y^(2)+12xy

Check whether the following are perfect squares or not : (a) 64x^(2) + 81y^(2) - 144 xy (b) 4x^(2) + 8y^(2) + 16 xy

If A=4x^(2)+y^(2)-6xy, B=3y^(2)+12x^(2)+8xy, C=6x^(2)+8y^(2)+6xy Find (i) A+B+C (ii) (A-B)-C

Equation of the parabola whose focus is centre of the circle " x^(2)+y^(2)=4x+6y " and whose directrix is the line " x-y=0 " , is A) " x^(2)+y^(2)+2xy-8x-12y+26=0 " B ) " x^(2)+y^(2)-2xy-8x-12y-26=0 " C) " x^(2)+y^(2)+2xy+8x+12y+26=0 " D) " x^(2)+y^(2)-2xy-8x-12y+26=0 "

Equation of the parabola whose focus is centre of the circle " x^(2)+y^(2)=4x+6y " and whose directrix is the line " x-y=0 " is A) " x^(2)+y^(2)+2xy-8x-12y+26=0 B ) " x^(2)+y^(2)-2xy-8x-12y-26=0 C) " x^(2)+y^(2)+2xy+8x+12y+26=0 D) " x^(2)+y^(2)-2xy-8x-12y+26=0