Jawabanmu

2014-08-15T14:15:46+07:00
1) (2x-3x) (4y-5y) = -x-y
2) -2x+4y + (3x-y) = (-2x+3x)(4y-y) = x+3y
3) -6x+3xy+3xy-3y² = -6x+6xy-3y²
4) 3xy-4x²-8xy = -4x²-5xy
2014-08-15T14:17:27+07:00
1) 2x+4y - 3x-5y = -x-y
2) -(2x-4y)+(3x-y) = -2x+4y+3x-y = x+3y
3) -3x (2x-y)+3y (x-y)= -6x^2+3xy+3xy-3y^2 = -6x^2+6xy-3y^2
4) 3xy-2x (x+4y) = 3xy-2x^2-8xy = -5xy-2x^2

^=pangkat