Rút gọn:
A=\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Những câu hỏi liên quan
Rút gọn:
a, A= \(3-\left|3-x\right|\)
b, B= \(\left|x-6\right|+\left|6-x\right|-2\)
c, C= \(\left|-x-1\right|+\left|-x-5\right|-x\)
Rút gọn:
a, A= \(3-\left|3-x\right|\)
b, B= \(\left|x-6\right|+\left|6-x\right|-2\)
c, C= \(\left|-x-1\right|+\left|-x-5\right|-x\)
Rút gọn: \(\left(a+b+c\right)^3-\left(b+c-a\right)^3-6a\left(b+c\right)^2\)
Rút gọn: \(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
bạn tham khảo link này nhé:
https://olm.vn/hoi-dap/detail/101383958371.html
#hok tốt#
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\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
\(=a^3+b^3+c^3+a^3-b^3-c^3-6a\left(b^2+c^2\right)\)
\(=\left(a^3+a^3\right)+\left(b^3-b^3\right) +\left(c^3-c^3\right)-6a\left(b^2+c^2\right)\)
\(=2a^3-6a\left(b^2+c^2\right)\)
\(=2a^2\cdot a-6a\left(b^2+c^2\right)\)
\(=a\left[2a^2-6\left(b^2+c^2\right)\right]\)
\(\text{Chắc là vậy !}\)
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Link nè :
https://olm.vn/hoi-dap/detail/101383958371.html
k mk nhé mk hông giải nên mk cho bn link rùi nè
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Xem thêm câu trả lời
Rút gọn:
A=\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Đặt b+c=x ta được:
A=(a+x)3+(a-x)3-6a.x2
=a3+3a2x+3ax2+x3+a3-3a2x+3ax2-x3-6ax2
=2a3
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Rút gọn biểu thức:
\(A=\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
\(A=\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
\(=\left[a+\left(b+c\right)\right]^3+\left[a-\left(b+c\right)\right]^3-6a\left(b+c\right)^2\)
\(=a^3+3a^2\left(b+c\right)+3a\left(b+c\right)^2+\left(b+c\right)^3+a^3-3a^2\left(b+c\right)+3a\left(b+c\right)^2-\left(b+c\right)^3-6a\left(b+c\right)^2\)
\(=2a^3\)
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Rút gọn:
A=\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Rút gon biểu thức sau:
\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Rút gọn:
A=\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
\(A=\left[a+\left(b+c\right)\right]^3+\left[a-\left(b+c\right)\right]^3-6a\left(b+c\right)^2\)
\(=a^3+3a^2\left(b+c\right)+3a\left(b+c\right)^2+\left(b+c\right)^3+a^3-3a^2\left(b+c\right)+3a\left(b+c\right)^2-\left(b+c\right)^3-6a\left(b+c\right)^2\)
\(=2a^3+6a\left(b+c\right)^2-6a\left(b+c\right)^2=2a^3\)
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