22,2x+4y-8xy-1

Add 4x^2-7xy+6y^2, 4x^2+7xy-6y^2, 4xy-8y^2

Add: 17x+10y-12xy-13,18-7x-10y+8xy,4xy

Evaluate : 3x^(2) + 5xy - 4y^(2) + x^(2) - 8xy - 5y^(2)

Show that two pairs of lines 3x^(2)+8xy-3y^(2)=0 and 3x^(2)+8xy-3y^(2)+2x-4y-1=0 forms a square.

The equations of the diagonals of the square formed by the pairs of straight lines 3x^(2)+8xy-3y^(2)=0 and 3x^(2)+8xy-3y^(2)+2x-4y-1=0 are