ok so you will have to expand it. so in the first bracket the X Y and +3 will need to be multiplied to each of the variables in the second bracket. so what you need to do is X in the first bracket multiplied with X from the second bracket. then y then - 4 secondly you need to multiply the y from the first bracket to all the three. finally multiply 3 to all the three variables. after doing all that u should get x^2+xy-4x+xy+y^2-4y+3x+3y-12 then combine like terms and u get. x^2+2xy-x-y+y^2-12
