Question

me ajude a reduzir as expressões: 2x -5y + 7x - 9x - 4y

Answer 1

2x -5y +7x -9x -4y=0
9x -9y -9x=0
0x-9y=0
9y=0

Answer 2

2x -5y + 7x - 9x - 4y

2x + 7x - 9x - 5y - 4y

9x - 9x - 9y       ⇒    cancela 9x - 9x 
  
    - 9y