Ta có: \(\sqrt{8-2\sqrt{15}}-\sqrt{\left(\sqrt3-2\sqrt5\right)^2}\)
\(=\sqrt{\left(\sqrt5-\sqrt3\right)^2}-\left|\sqrt3-2\sqrt5\right|\)
\(=\sqrt5-\sqrt3-\left(2\sqrt5-\sqrt3\right)=\sqrt5-\sqrt3-2\sqrt5+\sqrt3=-\sqrt5\)
√(5+2√6)+√8-2√15. √4+2√3+√4-2√3-5√3-2√2-5√3+√8
Rút gọn: \(M=\dfrac{8}{\sqrt{5}-\sqrt{3}}+\dfrac{7}{\sqrt{3}-2}+\dfrac{4}{\sqrt{2}-1}+\dfrac{3\sqrt{5}-\sqrt{15}}{\sqrt{15}}\)
rút gọn hộ mik vs
4)\(\sqrt{8+2\sqrt{15}}\) -\(\sqrt{8-2\sqrt{15}}\)
5)\(\sqrt{5+2\sqrt{6}}\) +\(\sqrt{8-2\sqrt{15}}\)
Thực hiện từng bước của phép tính:
1.\(\left(\sqrt{2}+1\right)^3-\left(\sqrt{2}-1\right)^3\)
2.\(\sqrt{4-\sqrt{15}}+\sqrt{4+\sqrt{15}}-2\sqrt{3-\sqrt{5}}\)
3.\(\dfrac{10+2\sqrt{10}}{\sqrt{5}+\sqrt{2}}+\dfrac{8}{1-\sqrt{5}}\)
4.\(\sqrt{\dfrac{2-\sqrt{3}}{2+\sqrt{3}}}+\sqrt{\dfrac{2+\sqrt{3}}{2-\sqrt{3}}}\)
Thu gọn
a) A=\(\dfrac{2\left(\sqrt{2}+\sqrt{6}\right)}{3\sqrt{2+\sqrt{3}}}\) b)B=\(\sqrt{8-2\sqrt{15}}-\sqrt{\left(3-3\sqrt{5}\right)^2}\)
c) C=\(2\sqrt{8\sqrt{3}-2\sqrt{5\sqrt{3}}-3\sqrt{20\sqrt{3}}}\)
1, tính a/ (3+√5)(√10 - √2)√(3-√5)
b/[√2-√(3-√5)].√2
c/(√10 + √6).√(8-2√15)
2, tìm x biết a/ √(x+5)=1+√x
b/√x + √(x-1)=1
c/ √(3-x) + √(x-5)=10
3, phân tích đa thức thành nhân tử:
a/ ab+b√a+√a+1 với a ≥0
b/ x-2√xy + y với x,y ≥ 0
c/√xy + 2√x - 3√y -6 với x,y ≥ 0
4, chứng minh rằng a/ (4+√15).(√10-√6).√(4-√15)=2
b/ √a + √b > √(a+b) (a,b>0)
5, Cho √(8-a) + √(5+a) = 5 tính √[(8-a).(5+a)]
6, rút gọn √(7+2√10)-√15
P/s : mn giúp e với nha
a)\(\frac{4}{\sqrt{5}-1}+\frac{3}{\sqrt{5}-2}+\frac{16}{\sqrt{5}-3}\)
b)\(\frac{2}{\sqrt{8-2\sqrt{15}}}-\frac{1}{\sqrt{5-2\sqrt{6}}}-\frac{3}{\sqrt{7+2\sqrt{10}}}\)
c)\(\frac{8+2\sqrt{2}}{3-\sqrt{2}}-\frac{2+3\sqrt{2}}{\sqrt{2}}+\frac{\sqrt{2}}{1-\sqrt{2}}\)
d)\(\sqrt{1+\frac{\sqrt{3}}{2}}-\frac{\sqrt{8-\sqrt{15}}}{\sqrt{30}-\sqrt{2}}\)
\(\dfrac{\sqrt{15}-\sqrt{5}}{\sqrt{3}-1}+\dfrac{5-2\sqrt{5}}{2\sqrt{5}-4}\)
\(\left(\sqrt{3}+1\right).\dfrac{\sqrt{3}-3}{2\sqrt{3}}\)
\(\dfrac{3\sqrt{18}-2\sqrt{8}}{\sqrt{50}}\)
tính
a.\(\sqrt{8+2\sqrt{15}}-\sqrt{8-2\sqrt{15}}\)
b. \(\sqrt{5+2\sqrt{6}}+\sqrt{5-2\sqrt{6}}\)
