Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
4. (3/4-81)(3^2/5-81)(3^3/6-81)....(3^6/9-81).....(3^2011/2014-81)
mà 3^6/9-81=0 => (3/4-81)(3^2/5-81)....(3^2011/2014-81)=0
a: ĐKXĐ: 2x-10>=0
=>2x>=10
=>x>=5
b: \(\sqrt{A^2B}=\sqrt{A^2}\cdot\sqrt{B}=\left|A\right|\cdot\sqrt{B}\)
\(\sqrt{72}=\sqrt{36\cdot2}=6\sqrt{2}\)
c: \(A=\sqrt{16}+\sqrt{81}=4+9=13\)
\(B=\sqrt{\dfrac{\left(15\sqrt{5}+5\sqrt{200}-3\sqrt{450}\right)}{\sqrt{10}}}\)
\(=\sqrt{\dfrac{15}{\sqrt{2}}+5\sqrt{20}-3\sqrt{45}}\)
\(=\sqrt{\dfrac{15\sqrt{2}+2\sqrt{5}}{2}}=\sqrt{\dfrac{30\sqrt{2}+4\sqrt{5}}{4}}\)
\(=\dfrac{\sqrt{30\sqrt{2}+4\sqrt{5}}}{2}\)
\(C=\dfrac{3+2\sqrt{3}}{\sqrt{3}}+\dfrac{2+\sqrt{2}}{1+\sqrt{2}}-\left(2+\sqrt{3}\right)\)
\(=\dfrac{\sqrt{3}\left(2+\sqrt{3}\right)}{\sqrt{3}}-\left(2+\sqrt{3}\right)+\dfrac{\sqrt{2}\left(\sqrt{2}+1\right)}{\sqrt{2}+1}\)
\(=2+\sqrt{3}-2-\sqrt{3}+\sqrt{2}=\sqrt{2}\)
a)x+(-81)-(11-81)
=x-81-11+81
=x-11
b)(-1-x+2)+1
=-1-x+2+1
=-x+2
c)15-(11-x)+(11-15)
=15-11+x+11-15
=x
d)15-(15-x+202)+202
=15-15+x-202+202
=x
