單項式5X*2Y,3X*2Y*2,4YX*2的和為

單項式5X*2Y,3X*2Y*2,4YX*2的和為

5X*2Y+3X*2Y*2+4YX*2
=10XY+6XY+8XY
=(10+6+8)XY
=24XY