\(\sqrt{9a^2\left(b^2+4-4b\right)}\)Rút gọn và tìm giá trị
\(\sqrt{9a^2\left(b^2+4-4b\right)}\)Rút gọn và tìm giá trị
Bạn xem lại đề nha tìm giá trị nào vậy. .K có kết quả thì sao tìm..
\(\sqrt{9a^2\left(b^2-4b+4\right)}=\sqrt{\left[3a\cdot\left(b-2\right)\right]^2}=\left|3a\left(b-2\right)\right|\)
Rút gọn căn thức sau:
\(\sqrt{17+12\sqrt{2}}\) +\(\sqrt{9+4\sqrt{2}}\)
\(\sqrt{17+12\sqrt{2}}+\sqrt{9+4\sqrt{2}}\)
\(=\sqrt{\left(3+2\sqrt{2}\right)^2}+\sqrt{\left(2\sqrt{2}+1\right)^2}\)
\(=3+2\sqrt{2}+2\sqrt{2}+1\)
\(=4+4\sqrt{2}\)
\(\sqrt{17+12\sqrt{2}}+\sqrt{9+4\sqrt{2}}=\sqrt{\left(3+2\sqrt{2}\right)^2}+\sqrt{\left(2\sqrt{2}+1\right)^2}\)
\(=3+2\sqrt{2}+2\sqrt{2}+1=4+4\sqrt{2}\)
\(\sqrt{17+12\sqrt{2}}+\sqrt{9+4\sqrt{2}}=\sqrt{8+2.2\sqrt{2}.3+9}+\sqrt{8+2.2\sqrt{2}.1+1}=\sqrt{\left(2\sqrt{2}+3\right)^2}+\sqrt{\left(2\sqrt{2}+1\right)^2}=\left|2\sqrt{2}+3\right|+\left|2\sqrt{2}+1\right|=2\sqrt{2}+3+2\sqrt{2}+1=4\sqrt{2}+4\)
BÀi 3: Áp dụng quy tắc nhân hai căn bậc hai, hãy tính:
a)\(\sqrt{0,4}.\sqrt{64}\) b) \(\sqrt{5,2}.\sqrt{1,3}\) c) \(\sqrt{12,1}.\sqrt{360}\)
\(a.\sqrt{0,4}.\sqrt{64}=\sqrt{0,4.64}=\sqrt{25,6}\)
\(b.\sqrt{5,2}.\sqrt{1,3}=\sqrt{5,2.1,3}=\sqrt{6,76}=2.6\)
\(c.\sqrt{12,1}.\sqrt{360}=\sqrt{12,1.360}=\sqrt{4356}=66\)
a) √0,4.6,4
b) √1,3.52.10
c) √2,7.5.1.5
√(64.4)/100=16/10=1.6
√(13.13.4)=26
√(9.3.5.5)/10=15√3/√10=15√30/10
tìm x không âm biết a,9-4 căn x=1 b,căn x/5=4 c,căn 7x<9 giúp mk với .mai hk rùi
a: =>4 căn x=8
=>căn x=2
=>x=4
b: =>x/5=16
=>x-80
c: =>0<=7x<81
=>0<=x<81/7
a) √0,4.√64
b) √5,2.√1,3
c) √12,1.√360
a) \(\sqrt{0,4}.\sqrt{64}=\dfrac{\sqrt{10}}{5}.8=\dfrac{8\sqrt{10}}{5}\)
b) \(\sqrt{5,2}.\sqrt{1,3}=\sqrt{5,2.1,3}=\sqrt{\dfrac{169}{25}}=\dfrac{13}{5}=2,6\)
c) \(\sqrt{12,1}.\sqrt{360}=\sqrt{12,1.360}=\sqrt{121.36}=\sqrt{121}.\sqrt{36}=11.6=66\)
B1: Tính
a) \(.\sqrt{12,1.490}\)
b) \(\sqrt{72.32}\)
B2 : Rút gọn
a) \(\sqrt{48.75a^2}\)
b) \(\sqrt{8a^2}.\sqrt{18a^4}\) với a<0
c) \(\sqrt{a}.\sqrt{\dfrac{9}{a}}\left(a>0\right)\)
d)\(\sqrt{4-2\sqrt{3}}-\sqrt{3}\)
HELP ME !
B1: a) \(\sqrt{12,1.490}=\sqrt{12,1.10.49}=\sqrt{121}.\sqrt{49}=11.7=77\)
b) \(\sqrt{72.32}=\sqrt{36.2.32}=\sqrt{36}.\sqrt{64}=6.8=48\)
B2: a) \(\sqrt{48.75a^2}=\sqrt{3600a^2}=60\left|a\right|\)
b) \(\sqrt{8a^2}.\sqrt{18a^4}=\sqrt{8a^2.18a^4}=\sqrt{144a^6}=-12a^3\)
c) \(\sqrt{a}.\sqrt{\dfrac{9}{a}}=\sqrt{a.\dfrac{9}{a}}=\sqrt{9}=3\)
d) \(\sqrt{4-2\sqrt{3}}-\sqrt{3}=\sqrt{\left(\sqrt{3}-1\right)^2}-\sqrt{3}=\sqrt{3}-1-\sqrt{3}=-1\)
CM hằng đẳng thức
\(\dfrac{\left|a-5\right|}{5-a}+\sqrt{a-6}=\dfrac{a-7}{1+\sqrt{a-6}}\)
ĐKXĐ: a>=6
\(\dfrac{a-7}{\sqrt{a-6}+1}=\sqrt{a-6}-1\)
\(A=\dfrac{\left|a-5\right|}{5-a}+\sqrt{a-6}\)
\(=\dfrac{a-5}{5-a}+\sqrt{a-6}=\sqrt{a-6}-1\)(ĐPCM)
Cho x,y \(\in\)Z thõa mãn \(\dfrac{x^2-1}{2}=\dfrac{y^2-1}{3}\). Chứng minh \(x^2-y^2⋮40\)
thực hiện phép tính
a) \(\sqrt{\dfrac{1}{9}.0,4.64}\)
b)\(\sqrt{11\dfrac{1}{9}}\)
c) \(\sqrt{\dfrac{1}{44}.2\dfrac{2}{49}}\)
d) \(\sqrt{1\dfrac{9}{16}.2\dfrac{1}{4}.2\dfrac{7}{9}}\)
a) \(\sqrt{\dfrac{1}{9}.0,4.64}=\sqrt{\dfrac{1}{9}}.\sqrt{0,4}.\sqrt{64}=\dfrac{1}{3}.\dfrac{\sqrt{10}}{5}.8=\dfrac{8\sqrt{10}}{15}\)
b) \(\sqrt{11\dfrac{1}{9}}=\sqrt{\dfrac{100}{9}}=\dfrac{\sqrt{100}}{\sqrt{9}}=\dfrac{10}{3}\)
c) \(\sqrt{\dfrac{1}{44}.2\dfrac{2}{49}}=\sqrt{\dfrac{1}{44}}.\sqrt{\dfrac{100}{49}}=\dfrac{\sqrt{11}}{22}.\dfrac{10}{7}=\dfrac{5\sqrt{11}}{77}\)
d) \(\sqrt{1\dfrac{9}{16}.2\dfrac{1}{4}.2\dfrac{7}{9}}\sqrt{\dfrac{25}{16}.\dfrac{9}{4}.\dfrac{25}{9}}=\sqrt{\dfrac{25}{16}}.\sqrt{\dfrac{9}{4}}.\sqrt{\dfrac{25}{9}}=\dfrac{5}{4}.\dfrac{3}{2}.\dfrac{5}{3}=\dfrac{25}{8}\)