Chọn câu đúng? 1/(x + 2) - 1/(x + 2)(4x + 7) = 4x/(x + 2)(4x + 7)

1x+2−1(x+2)(4x+7)=4x(x+2)(4x+7)

2−21x18−4+x12=75x−1636

1x+4−1x+5=1(x+4)(x+5)

2x−5+3xx2−25=4x+5x2−25