Chứng minh rằng: 1/41+1/42+1/43+..........+1/79+1/80>7/12
Chững minh rằng : 1/41 + 1/42 + 1/43 +... + 1/79 + 1/80 > 7/12
Chứng minh rằng :
1/41 + 1/42 + 1/43 + ... + 1/79 + 1/80 > 7/12
chứng minh rằng:
1/41+1/42+1/43+.....+1/79+1/80 >7/12
a, cho A = 9999931999 - 5555571997
Chứng minh rằng A chia hết cho 5
b, Chứng tỏ rằng :
\(\dfrac{1}{41}+\dfrac{1}{42}+\dfrac{1}{43}+....+\dfrac{1}{79}+\dfrac{1}{80}\) >\(\dfrac{7}{12}\)
Cho A = 1/41+1/42+1/43+...+1/78+1/79+1/80. Chứng tỏ: A > 7/12
a) cho A =999993^1999 - 555557^4997. Chứng minh rằng A chia hết cho 5
b) Chứng tỏrằng : 1/41+1/42+1/43+...+1/79+1/80>7/12
Chứng minh rằng
a) 1/2 + 1/3 + 1/4 +...+1/63 > 2
b) 1/41 + 1/42 + 1/43 +...+1/79 + 1/80 > 7/12
CMR 1/41+1/42+1/43+...+1/79+7/80 <7/12
