Các câu hỏi tương tự
Chứng minh rằng:
a)\(a^3+b^3=\left(a+b\right)^3-3ab\left(a+b\right)\)
b)\(\left(a-b\right)^3+3ab\left(a-b\right)=a^3-b^3\)
c)\(\left(a+b\right)^2-\left(a-b\right)^2=4ab\)
24 tháng 10 2021 lúc 15:25
PTĐT thành nhân tử
a) \(A=a\left(b+c-a\right)^2+b\left(c+a-b\right)^2+c\left(a+b-c\right)^2+\left(a+b-c\right)\left(b+c-a\right)\left(c+a-b\right)\)
b) \(B=\left(a+b-c\right)^3+\left(a-b+c\right)^3+\left(-a+b+c\right)^3-\left(a+b+c\right)^3\)
c) \(C=bc\left(a+b\right)\left(b-c\right)-ac\left(b+d\right)\left(a-c\right)+ab\left(c+d\right)\left(c-b\right)\)
left(a+b+cright)^3-a^3-b^3-c^3left[left(a+bright)+cright]^3-a^3-b^3-c^3left(a+bright)^3+3left(a+bright)^2c+3left(a+bright)c^2+c^3-a^3-b^3-c^3a^3+3a^2b+3ab^2+b^3+3cleft(a^2+2ab+b^2right)+3ac^2+3bc^2-a^3-b^33a^2b+3ab^2+3a^2c+6abc+3b^2c+3ac^2+3bc^23left(a^2b+ab^2+a^2c+ac^2+b^2c+bc^2+2abcright)3left[left(a^2b+ab^2right)+left(a^2c+abcright)+left(ac^2+bc^2right)+left(b^2c+abcright)right]3left[ableft(a+bright)+acleft(a+bright)+c^2left(a+bright)+bcleft(a+bright)right]3left(a+bright)left(ab+ac+c^2+bcrigh...
Đọc tiếp
\(\left(a+b+c\right)^3-a^3-b^3-c^3\)
\(=\left[\left(a+b\right)+c\right]^3-a^3-b^3-c^3\)
\(=\left(a+b\right)^3+3\left(a+b\right)^2c+3\left(a+b\right)c^2+c^3-a^3-b^3-c^3\)
\(=a^3+3a^2b+3ab^2+b^3+3c\left(a^2+2ab+b^2\right)+3ac^2+3bc^2-a^3-b^3\)
\(=3a^2b+3ab^2+3a^2c+6abc+3b^2c+3ac^2+3bc^2\)
\(=3\left(a^2b+ab^2+a^2c+ac^2+b^2c+bc^2+2abc\right)\)
\(=3\left[\left(a^2b+ab^2\right)+\left(a^2c+abc\right)+\left(ac^2+bc^2\right)+\left(b^2c+abc\right)\right]\)
\(=3\left[ab\left(a+b\right)+ac\left(a+b\right)+c^2\left(a+b\right)+bc\left(a+b\right)\right]\)
\(=3\left(a+b\right)\left(ab+ac+c^2+bc\right)\)
\(=3\left(a+b\right)\left[a\left(b+c\right)+c\left(b+c\right)\right]\)
\(=3\left(a+b\right)\left(b+c\right)\left(c+b\right)\)
65. Phân tích đa thức thành nhân tửa) ableft(a+bright)-bcleft(b+cright)+acleft(a-cright)b) aleft(b^2+c^2right)+bleft(c^2+a^2right)+cleft(a^2+b^2right)+2abcc) left(a+bright)left(a^2-b^2right)+left(b+cright)left(b^2+c^2right)+left(c+aright)left(c^2+a^2right)d) a^3left(b-cright)+b^3left(c-aright)+c^3left(a-bright)e) a^3left(c-b^2right)+b^3left(a-c^2right)+c^3left(b-a^2right)+abcleft(abc-1right)
Đọc tiếp
65. Phân tích đa thức thành nhân tử
a) \(ab\left(a+b\right)-bc\left(b+c\right)+ac\left(a-c\right)\)
b) \(a\left(b^2+c^2\right)+b\left(c^2+a^2\right)+c\left(a^2+b^2\right)+2abc\)
c) \(\left(a+b\right)\left(a^2-b^2\right)+\left(b+c\right)\left(b^2+c^2\right)+\left(c+a\right)\left(c^2+a^2\right)\)
d) \(a^3\left(b-c\right)+b^3\left(c-a\right)+c^3\left(a-b\right)\)
e) \(a^3\left(c-b^2\right)+b^3\left(a-c^2\right)+c^3\left(b-a^2\right)+abc\left(abc-1\right)\)
65. Phân tích đa thức thành nhân tửa) ableft(a+bright)-bcleft(b+cright)+acleft(a-cright)b) aleft(b^2+c^2right)+bleft(c^2+a^2right)+cleft(a^2+b^2right)+2abcc) left(a+bright)left(a^2-b^2right)+left(b+cright)left(b^2-c^2right)+left(c+aright)left(c^2-a^2right)d) a^3left(b-cright)+b^3left(c-aright)+c^3left(a-bright)e) a^3left(c-b^2right)+b^3left(a-c^2right)+c^3left(b-a^2right)+abcleft(abc-1right)
Đọc tiếp
65. Phân tích đa thức thành nhân tử
a) \(ab\left(a+b\right)-bc\left(b+c\right)+ac\left(a-c\right)\)
b) \(a\left(b^2+c^2\right)+b\left(c^2+a^2\right)+c\left(a^2+b^2\right)+2abc\)
c) \(\left(a+b\right)\left(a^2-b^2\right)+\left(b+c\right)\left(b^2-c^2\right)+\left(c+a\right)\left(c^2-a^2\right)\)
d) \(a^3\left(b-c\right)+b^3\left(c-a\right)+c^3\left(a-b\right)\)
e) \(a^3\left(c-b^2\right)+b^3\left(a-c^2\right)+c^3\left(b-a^2\right)+abc\left(abc-1\right)\)
8 tháng 1 2022 lúc 14:52
Chứng minh rằng \(\left(a+b+c\right)^2-\dfrac{3}{4}\left[\left(b-c\right)^2+\left(c-a\right)^2+\left(a-b^2\right)\right]>3\)
với a,b,c là các số thực
Đề có sai ko mọi ngừi
66. Phân tích đa thức thành nhân tử:a) aleft(b+cright)^2left(b-cright)+bleft(c+aright)^2left(c-aright)+cleft(a+bright)^2left(a-bright)b) aleft(b-cright)^3+bleft(c-aright)^3+cleft(a-bright)^3c) a^2b^2left(a-bright)+b^2c^2left(b-cright)+c^2a^2left(c-aright)d) aleft(b^2+c^2right)+bleft(c^2+a^2right)+cleft(a^2+b^2right)-2abc-a^3-b^3-c^3e) a^4left(b-cright)+b^4left(c-aright)+c^4left(a-bright)
Đọc tiếp
66. Phân tích đa thức thành nhân tử:
a) \(a\left(b+c\right)^2\left(b-c\right)+b\left(c+a\right)^2\left(c-a\right)+c\left(a+b\right)^2\left(a-b\right)\)
b) \(a\left(b-c\right)^3+b\left(c-a\right)^3+c\left(a-b\right)^3\)
c) \(a^2b^2\left(a-b\right)+b^2c^2\left(b-c\right)+c^2a^2\left(c-a\right)\)
d) \(a\left(b^2+c^2\right)+b\left(c^2+a^2\right)+c\left(a^2+b^2\right)-2abc-a^3-b^3-c^3\)
e) \(a^4\left(b-c\right)+b^4\left(c-a\right)+c^4\left(a-b\right)\)
Phân tích đa thức thành nhân tử :a) âleft(b+cright)^2left(b-cright)+bleft(c+aright)^2left(c-aright)+cleft(a+bright)^2left(a-bright)b) aleft(b-cright)^3+bleft(c-aright)^3+cleft(a-bright)^3c) a^2b^2left(a-bright)+b^2c^2left(b-cright)+c^2a^2left(c-aright)d) aleft(b^2+c^2right)+bleft(c^2+a^2right)+cleft(a^2+b^2right)-2abc-a^3-b^3-c^3e) a^4left(b-cright)+b^4left(c-aright)+c^4left(a-bright)
Đọc tiếp
Phân tích đa thức thành nhân tử :
a) \(â\left(b+c\right)^2\left(b-c\right)+b\left(c+a\right)^2\left(c-a\right)+c\left(a+b\right)^2\left(a-b\right)\)
b) \(a\left(b-c\right)^3+b\left(c-a\right)^3+c\left(a-b\right)^3\)
c) \(a^2b^2\left(a-b\right)+b^2c^2\left(b-c\right)+c^2a^2\left(c-a\right)\)
d) \(a\left(b^2+c^2\right)+b\left(c^2+a^2\right)+c\left(a^2+b^2\right)-2abc-a^3-b^3-c^3\)
e) \(a^4\left(b-c\right)+b^4\left(c-a\right)+c^4\left(a-b\right)\)
1 tháng 10 2016 lúc 9:37
Phân tích đa thức sau thành nhân tử:
1) (b-c)(a^3-b^3)-(a-b)(b^3-c^3)
2) \(\left(b-c\right)\left[a\left(b+c\right)^2-b\left(c+a\right)^2\right]-\left(a-b\right)\left[b\left(c+a\right)^2+c\left(a+b\right)^2\right]\)