a.
C= 5x7/2x1x7 + 4x7/1x11x7 + 3x7/11x2x7 + 1x7/2x15x7 + 13x7/15x4x7
C= 7x (5/2x7 + 4/7x11 + 3/11x14 + 1/14x15 + 13/15x28)
C= 7x ( 1/2 -1/7 +1/7 -1/11 +1/11 -1/14 +1/14 - 1/15 +1/15 -1/28)
C= 7x(1/2 - 1/28)
C= 7x 13/28
C= 13/4
Vậy C=13/4
\(B=\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{2}{2.15}+\frac{13}{15.4}\)
Tinh hop ly tong sau
B= \(\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
Tính:
\(\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
\(A=\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\) = ?
\(\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
\(B=\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
Tính tổng:
\(B=\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
Tính \(\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
tính \(\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
