HOC24
Lớp học
Môn học
Chủ đề / Chương
Bài học
x2-x-y2-y
=(x2-y2)-(x+y)
=(x-y)(x+y)-(x+y)
=(x+y)(x-y-1)
1.Was
2. weren't - were
3. wasn't - was
4. were - was
3. 25 + 15. 4 - 26 : 2
= 75 + 60 -13 =122
519 : 517 + 3: 7
= 52 + 3/7 = 25\(\frac{3}{7}\) = \(\frac{178}{7}\)