P=\(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{7}+...+\frac{1}{46}-\frac{1}{56}\)
P=\(1-\frac{1}{56}\)
P=\(\frac{55}{56}\)
P = 1 - 1/2 + 1/2 - 1/4 +.......+1/46 - 1/56
P = 1 - 1/56
P = 55/56 nha!
dễ thôi
P= 1/1.2 + 2/2.4 + 3/4.7 + ... + 10/46.56
P= 1- 1/2 + 1/2 - 1/4 + 1/4 -1/7 +... + 1/46 - 1/56
P=1 - 1/56
P=55/56
Ta có:
\(P=\frac{1}{1.2}+\frac{2}{2.4}+...+\frac{10}{46.56}=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{4}+...+\frac{1}{46}-\frac{1}{56}=1-\frac{1}{56}=\frac{55}{56}\)