Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
123 456 789 123 456 789 * 123 456 789 123 456 789 =
1.5241579e+34
1) (a+b).(a+b)=(a+b)2=a2+2ab+b2
2) (a-b)2=a2-2ab+b2
3) (a+b).(a-b)=a2-b2
4) (a+b)3=a3+3a2b+3ab2+b3
5) (a-b)3=a3-3a2b+3ab2-b3
6) (a+b).(a2-ab+b2)=a3+b3
7) (a-b).(a2+ab+b2)=a3-b3
mấy cái ày là hằng đẳng thức đáng nhớ mà
lấy a+a b+b
lấy b^2-a
lấy a.b b.a
a^3 +b
b^3-a
hai câu cuối thì mình k biết
1) \(\left(a+b\right).\left(a+b\right)=a.\left(a+b\right)+b.\left(a+b\right)=a^2+ab+b^2+ab\)
2) \(\left(a-b\right)^2=\left(a-b\right).\left(a-b\right)=a.\left(a-b\right)-b.\left(a-b\right)=a^2-ab-ab+b^2\)
\(=a^2+\left(-ab\right)+\left(-ab\right)+b^2\)
3) \(\left(a+b\right).\left(a-b\right)=a.\left(a-b\right)+b.\left(a-b\right)=a^2-ab+ab-b^2=a^2-b^2\)
\(=a^2+-\left(b^2\right)\)
4) \(\left(a+b\right)^3=\left(a+b\right).\left(a+b\right).\left(a+b\right)=a.\left(a+b\right).\left(a+b\right)+b.\left(a+b\right).\left(a+b\right)\)
\(=\left[a.\left(a+b\right)\right].\left(a+b\right)+\left[b.\left(a+b\right)\right].\left(a+b\right)=\left(a^2+ab\right).\left(a+b\right)+\left(ab+b^2\right).\left(a+b\right)\)
\(=a^2.\left(a+b\right)+ab.\left(a+b\right)+ab.\left(a+b\right)+b^2.\left(a+b\right)\)
\(=a^3+a^2b+a^2b+ab^2+a^2b+ab^2+b^2a+b^3\)
5) \(\left(a-b\right)^3=\left(a-b\right).\left(a-b\right).\left(a-b\right)=a.\left(a-b\right).\left(a-b\right)-b.\left(a-b\right).\left(a-b\right)\)
\(=\left(a^2-ab\right).\left(a-b\right)-\left(ba-b^2\right).\left(a-b\right)\)
\(=a^2.\left(a-b\right)-ab.\left(a-b\right)-ba.\left(a-b\right)+b^2.\left(a-b\right)\)
\(=a^3-a^2b-a^2b+ab^2-ba^2+b^2a-ba^2+b^2a-b^3\)
6) \(\left(a+b\right).\left(a^2-ab+b^2\right)=a.\left(a^2-ab+b^2\right)+b.\left(a^2-ab+b^2\right)\)
\(=a^3-a^2b+ab^2+ba^2-ab^2+b^3\)
\(=a^3+b^3\)
7) \(\left(a-b\right).\left(a^2+ab+b^2\right)=a.\left(a^2+ab+b^2\right)-b.\left(a^2+ab+b^2\right)\)
\(=a^3+a^2b+ab^2-ba^2-ab^2-b^3\)
\(=a^3-b^3\)
1 a^2+2ab+b^2
2 a^2-2ab+b^2
3 a^2-b^2
4 a^3+3a^2b+3ab^2+b^3
5 a^3-3a^2b+3ab^2-b^3
6 a^3+b^3
7 a^3-b^3
a) \(\left(a+b\right).\left(a-b\right)=a.\left(a-b\right)+b.\left(a-b\right)=a^2-ab+ba-b^2\)\(=a^2-b^2\)
b) \(\left(a+b\right)^3=\left(a+b\right).\left(a+b\right).\left(a+b\right)=a.\left(a+b\right).\left(a+b\right)+b.\left(a+b\right).\left(a+b\right)\)
\(=\left(a^2+ab\right).\left(a+b\right)+\left(ba+b^2\right).\left(a+b\right)\)\(=a^2.\left(a+b\right)+ab.\left(a+b\right)+ba.\left(a+b\right)+b^2.\left(a+b\right)\)
\(=a^3+a^2b+a^2b+ab^2+ba^2+b^2a+b^2a+b^3\)\(=a^3+3a^2b+3ab^2+b^3\)
c) \(\left(a+b\right).\left(a^2-ab+b^2\right)=a.\left(a^2-ab+b^2\right)+b.\left(a^2-ab+b^2\right)\)
\(=a^3-a^2b+ab^2+ba^2-ab^2+b^3\)\(=a^3+b^3\)
d) \(\left(a-b\right).\left(a^2+ab+b^2\right)=a.\left(a^2+ab+b^2\right)-b.\left(a^2+ab+b^2\right)\)
\(=a^3+a^2b+ab^2-ba^2-ab^2-b^3\)\(=a^3-b^3\)
e) \(\left(a-b\right)^3=\left(a-b\right).\left(a-b\right).\left(a-b\right)=a.\left(a-b\right).\left(a-b\right)-b.\left(a-b\right).\left(a-b\right)\)
\(=\left(a^2-ab\right).\left(a-b\right)-\left(ba-b^2\right).\left(a-b\right)\)\(=a^2.\left(a-b\right)-ab.\left(a-b\right)-ba.\left(a-b\right)+b^2.\left(a-b\right)\)
\(=a^3-a^2b-a^2b+ab^2-ba^2+b^2a+b^2a-b^3\)
\(=a^3-3a^2b+3ab^2-b^3\)
1) (a+b).(a+b)=(a+b)2=a2+2ab+b2
2) (a-b)2=a2-2ab+b2
3) (a+b).(a-b)=a2-b2
4) (a+b)3=a3+3a2b+3ab2+b3
5) (a-b)3=a3-3a2b+3ab2-b3
6) (a+b).(a2-ab+b2)=a3+b3
7) (a-b).(a2+ab+b2)=a3-b3
1) (a+b)3=(a+b)(a+b)(a+b)=(a2+ab+ab+b2)(a+b)=(a2+2ab+b2)(a+b)(a3+2a2b+ab2)+(a2b+2ab2+b3)=a3+2a2b+ab2+a2b+2ab2+b3
=a3+3a2b+3ab2+b3
71234567891234567892 = 15 241 578 780 673 678 515 622 620 750 190 521
9880722529880722522 = 976 286 777 124 925 055 320 989 783 172 351 504
PHẢI TRÌNH BÀY CHI TIẾT NHA