Cho P= 1/2+1/3+1/4+...+1/48+1/49 và Q=1/49+2/48+...+48/2+49/1
hãy tính P/Q
cho p=1/2+1/3+1/4+…+1/47+1/48+1/49+1/50
q=1/49+2/48+3/49+…47/3+48/2+49/1
tính p/q
Cho P = 1/2 + 1/3 + 1/4 + ... + 1/48 + 1/49 + 1/50 và Q = 1/49 +2/48 +3/47 + ... + 48/2 + 49/1.
Hãy tính P/Q
Q = \(\frac{1}{49}+\frac{2}{48}+\frac{3}{47}+...+\frac{48}{2}+\frac{49}{1}\)
Cộng 1 vào mỗi phân số trong 48 phân số đầu, trừ phân số cuối đi 48, ta được :
Q = \(\left(\frac{1}{49}+1\right)+\left(\frac{2}{48}+1\right)+\left(\frac{3}{47}+1\right)+...+\left(\frac{48}{2}+1\right)+1\)
Q = \(\frac{50}{49}+\frac{50}{48}+\frac{50}{47}+...+\frac{50}{2}+1\)
Q = \(\frac{50}{49}+\frac{50}{48}+\frac{50}{47}+...+\frac{50}{2}+\frac{50}{50}\)
đưa phân số cuối lên đầu :
Q = \(\frac{50}{50}+\frac{50}{49}+\frac{50}{48}+\frac{50}{47}+...+\frac{50}{2}\)
Q = \(50.\left(\frac{1}{50}+\frac{1}{49}+\frac{1}{48}+\frac{1}{47}+...+\frac{1}{2}\right)\)
Q = 50 . A
Vậy \(\frac{P}{Q}=\frac{1}{50}\)
Cho :P=1/2+1/3+1/4+.....+1/48+2/49+3/50
Q=1/49+2/48+3/47+....+48/2+49/1
Tính P/Q
Các bạn cố gắng giúp mình nha !!!
Cho P=1/2+1/3+1/4+...+1/50
Q=1/49+2/48+3/47+...+48/2+49/1
Tính P/Q
Cho S = \(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{48}+\frac{1}{49}+\frac{1}{50}\)và P = \(\frac{1}{49}+\frac{2}{48}+\frac{3}{47}+...+\frac{48}{2}+\frac{49}{1}\). Tính \(\frac{S}{P}\)
p=\(\frac{1}{49}+\frac{2}{48}+\frac{3}{47}+...+\frac{48}{2}+49\)
=\(\left(\frac{1}{49}+1\right)+\left(\frac{2}{48}+1\right)+\left(1+\frac{3}{47}\right)+...+\left(1+\frac{48}{2}\right)+\frac{50}{50}\)
=\(\frac{50}{50}+\frac{50}{49}+\frac{50}{48}+...+\frac{50}{2}\)
=\(50\left(\frac{1}{50}+\frac{1}{49}+\frac{1}{48}+...+\frac{1}{2}\right)\)
p=50*S
\(\frac{S}{\text{p}}=\frac{1}{50}\)
Cho S=1/2+1/3+1/4+....+1/48+1/49+1/5000 và P=1/49+2/48+3/47+....+48/2+49/2.Hãy tính S/P
Cho S =1/2 +1/3 + 1/4+...+1/48+1/49+1/50
Và P = 1/49 + 2/48 + 3/47+...+ 48/2 + 49/1
Tính S / P
cho P=1/2+1/3+1/4+...........+1/48+1/49+1/50 và Q=1/49+2/48+3/47+........+47/3+48/2+49/1
Cho P=\(\frac{1}{2}+\frac{1}{3}+......+\frac{1}{48}+\frac{1}{49}\)+ \(\frac{1}{50}\) ;Q= \(\frac{1}{49}+\frac{2}{48}+.....+\frac{48}{2}+\frac{49}{1}\)
Tính \(\frac{P}{Q}\)
Cho S=\(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+.........+\frac{1}{48}+\frac{1}{49}+\frac{1}{50}\) VÀ
P=\(\frac{1}{49}+\frac{2}{48}+\frac{3}{47}+......+\frac{48}{2}+\frac{49}{1}\)
Tính \(\frac{S}{P}\)