Chiều rộng là :

\(1,8\times\dfrac{5}{9}=1\left(km\right)\)

Diện tích khu đất là :

\(1,8\times1=1,8\left(km^2\right)=180\left(ha\right)\)

khi đó nhiệt độ trong kho là số độ C

\(-4,7-\dfrac{8}{5}=-4,7-1,6=-6,3\left(^oC\right)\)

Canh của hình vuông là :\(18,2:4=4,55\left(m\right)\)

Diện tích hình vuông là  \(4,55\times4,55=20,7025\left(m^2\right)\)

\(a,A=\dfrac{3}{7}-\dfrac{5}{2}-\left(-\dfrac{3}{7}\right)+\sqrt{\dfrac{1}{4}}-2022^0\\ =\dfrac{3}{7}-\dfrac{5}{2}+\dfrac{3}{7}+\dfrac{1}{2}-1\\ =\left(\dfrac{3}{7}+\dfrac{3}{7}\right)+\left(-\dfrac{5}{2}+\dfrac{1}{2}\right)-1\\ =\dfrac{6}{7}-2-1\\ =\dfrac{6}{7}-3\\=\dfrac{6-3\times7}{7}\\ =\dfrac{6-21}{7}=-\dfrac{15}{7}\)

\(b,B=\left(-0,125\right)^5.8^5+\left[\dfrac{16}{81}:\left(-\dfrac{4}{3}\right)^2+\dfrac{24^3}{12^3}\right]-1^{2021}\\ =\left(-0,125\times8\right)^5+\left[\dfrac{16}{81}:\dfrac{16}{9}+2^3\right]-1\\ =\left(-1\right)^5+\left(\dfrac{16}{81}\times\dfrac{9}{16}+2^3\right)-1\\ =-1+\left(\dfrac{1}{9}+8\right)-1\\ =-1+\left(\dfrac{1}{9}+\dfrac{72}{9}\right)-1=-2+\dfrac{73}{9}\\ =\dfrac{-2.9+73}{9}\\ =\dfrac{55}{9}\)

bn có bt hoidap247 ko z :)

=> :))) có 

Chứng mính trên 

\(41-\left(115+41\right)-\left[-15-\left(-219\right)\right]\\ =41-115-41-\left[-15+219\right]\\ =\left(41-41\right)-115+15-219\\ =0+\left(-115+15\right)-219\\ =0-100-219\\ =-319\)

a, Các cặp so le trong

\(\widehat{A_2};\widehat{B_4}\\ \widehat{A_3};\widehat{B_3}\\ \widehat{D_3};\widehat{C_1}\\ \widehat{D_4};\widehat{C_2}\)

b, Các cặp đồng vị

\(\widehat{A_1};\widehat{B_3}\\ \widehat{A_4};\widehat{B_4}\\ \widehat{B_2};\widehat{A_2}\\ \widehat{B_1};\widehat{A_3}\\ \widehat{D_3};\widehat{C_3}\\ \widehat{D_4};\widehat{C_4}\\ \widehat{D_1};\widehat{C_1}\\ \widehat{D_2};\widehat{C_2}\)

\(a,23-42=-19\\ b,21+\left(-67\right)+\left(-21\right)+120+67\\ =\left[21+\left(-21\right)\right]+\left[\left(-67\right)+67\right]+120\\ =0+0+120\\ =120\\ c,\left(-34+137\right)-\left(137-34+60\right)\\ =-34+137-137+34-60\\ =\left(-34+34\right)+\left(137-137\right)-60\\ =0+0-60\\ =-60\)

cx thường thoi :)))