B=13/28

B=1/7.(555/222+4444/1221+33333/244442+11/330+13/60

B= 1/7.(5/2+4/11+3/22+11/330+13/60)

B= 1/7.(1650/660+240/660+90/660+22/660+143/660)

B=1/7.143/44

B=143/308

k mk nha, k xong bình luận bên dưới mk k lại cho

\(B=\frac{1}{7}\left(\frac{5}{2}+\frac{4}{11}+\frac{3}{22}+\frac{11}{30}+\frac{13}{60}\right)\)

\(B=\frac{1}{7}\left(\frac{5}{2}+\frac{11}{22}+\frac{35}{60}\right)\)

quy đồng tính nốt ra \(B=\frac{43}{84}\)

Nhớ bấm   L I K E   cho mk nhá :))))

=0.4175277917

a) 2^x*(1+2+4+8) = 480

     2^x*15           = 480

     2^x                      = 480/15

      2^x                = 32

=>   x                 = 5.

b) Lười giải quá bạn ơi, thông cảm.

Xin lỗi, mình chỉ làm được câu 1 thôi

\(A=\frac{1}{7}\left(\frac{555}{222}+\frac{4444}{12221}+\frac{33333}{244442}+\frac{11}{330}+\frac{13}{60}\right)\)

\(A=\frac{1}{7}\left(\frac{5.111}{2.111}+\frac{4.1111}{11.1111}+\frac{3.11111}{22.11111}+\frac{11}{11.30}+\frac{13}{60}\right)\)

\(A=\frac{1}{7}\left(\frac{5}{2}+\frac{4}{11}+\frac{3}{22}+\frac{1}{30}+\frac{13}{60}\right)\)

\(A=\frac{1}{7}\left[\left(\frac{5}{2 }+\frac{1}{30}+\frac{13}{60}\right)+\left(\frac{4}{11}+\frac{3}{22}\right)\right]\)

\(A=\frac{1}{7}\left[\left(\frac{150}{60}+\frac{2}{60}+\frac{13}{60}\right)+\left(\frac{8}{22}+\frac{3}{22}\right)\right]\)

\(A=\frac{1}{7}\left(\frac{11}{4}+\frac{1}{2}\right)\)

\(A=\frac{1}{7}.\frac{13}{4}\)

\(A=\frac{13}{21}\)