a/

\(\sqrt{7+4\sqrt{3}}=\sqrt{2^2+2.2\sqrt{3}+\left(\sqrt{3}\right)^2}=\)

\(=\sqrt{\left(2+\sqrt{3}\right)^2}=2+\sqrt{3}\)

b/

\(\sqrt{21-12\sqrt{3}}=\sqrt{3^2-2.3.2\sqrt{3}+\left(2\sqrt{3}\right)^2}=\)

\(=\sqrt{\left(3-2\sqrt{3}\right)^2}=3-2\sqrt{3}\)

d/ \(\sqrt{15-6\sqrt{6}}+\sqrt{33-12\sqrt{6}}=\)

\(=\sqrt{3^2+2.3.\sqrt{6}+\left(\sqrt{6}\right)^2}=\sqrt{\left(3+\sqrt{6}\right)^2}=3+\sqrt{6}\)

mình cứ xét riêng từng cái 1 nhé

\(\dfrac{0,8:\left(\dfrac{4}{5}.1,25\right)}{0,65-\dfrac{1}{25}}=\dfrac{0,8:1}{0,61}=\dfrac{80}{61}\)

\(\dfrac{\left(1,08-\dfrac{2}{25}\right):\dfrac{4}{7}}{\left(6\dfrac{5}{9}-3\dfrac{1}{4}\right).2\dfrac{2}{17}}+\left(1,2.0,5\right):\dfrac{-4}{5}=\dfrac{1:\dfrac{4}{7}}{\dfrac{119}{36}.\dfrac{36}{17}}+\dfrac{3}{5}:\left(-\dfrac{4}{5}\right)\)

\(=\dfrac{\dfrac{7}{4}}{7}+-\dfrac{3}{4}=\dfrac{23}{2}\)

cộng và ta có KQ:/1563/122

Hình như bạn làm sai rồi

=6+12-3.3

=6+12-9

=18+9

=27

27

1/2×X+1/3×X+X=2022

= 1/2×X+1/3×X+Xx1 =2022

= X x ( 1/2 + 1/3 + 1) = 2022

= X x 11/6 = 2022

= X = 2022: 11/6

= X = 12132/11

\(\dfrac{1}{2}\times x+\dfrac{1}{3}\times x+x=2022\\ \Rightarrow\left(\dfrac{1}{2}+\dfrac{1}{3}+1\right)\times x=2022\\\Rightarrow \left(\dfrac{3}{6}+\dfrac{2}{6}+\dfrac{6}{6}\right)\times x=2022\\ \Rightarrow\dfrac{11}{6}\times x=2022\\ \Rightarrow x=2022:\dfrac{11}{6}\\ \Rightarrow x=2022\times\dfrac{6}{11}\\ \Rightarrow x=\dfrac{12132}{11}\)

Ai giúp đc ko ạ

11/30 , 2/5 , 5/6

a, Các phân số tối giản là: 1/3 ; 3/7 ; 101/131; 46/53.

b, Các phấn số cần rút gọn: 15/45 = 1/3 ; 120/350 = 12/35 ;  72/90 = 4/5