Respuesta:
• 2x · 3x = 6x2
• 5x · 2y =10xy
• -3x · 4y = -12xy
• 5x · (-2x) = -10x2
• 2 · (x + y) = 2x ,+2y
• -3 · (x + 2x) = -3x-6x =9x
• +2z+6z-5z+3z= 6z
• x+x+x+y+y-7y=3x-5y
• x-(2x-5x) = x+3x =4x
• (a+2a-3a)-(a+6a) = -7a
• (4x-2y) - (7x-5y)= -3x +3y