Bài 4; Chứng minh rằng:
a, ( 76 + 75 - 74 ) \(⋮\)77
b, ( 3636 - 910 )\(⋮\)45
c, ( 20161000+ 2006999 ) \(⋮\)2007
Tìm số dư khi chia A, B cho 2, biết:
\(A=\left(4^n+6^n+8^n+10^n\right)-\left(3^n+5^n+7^n+9^n\right)\)
\(B=2006^n+2007^n\)với \(n\in N\)
a) So sánh: \(9^{10}với8^9+7^9+6^9+...+1^9\)
b) Chứng minh: \(\left(36^{36}-9^{10}\right)⋮45\)
tính hợp lý
a) \(\frac{-1}{2}+\frac{-1}{9}-\frac{-3}{5}+\frac{1}{2006}-\left(\frac{-2}{7}\right)-\frac{7}{18}+\frac{4}{35}\)
b) \(\frac{1}{3}-\frac{3}{4}+\frac{3}{5}+\frac{1}{2007}-\frac{1}{36}+\frac{1}{15}-\frac{2}{9}\)
giúp mk nha
tính giá trị biểu thức
a, A=\(\frac{-1}{2}-\left[\frac{-3}{5}\right]+\left[\frac{-1}{9}\right]+\frac{1}{27}+\frac{7}{18}+\frac{4}{35}-\left[-\frac{2}{7}\right]\)
b, B=\(\frac{1}{3}-\frac{3}{4}-\left[\frac{-3}{5}-\frac{1}{57}+\frac{1}{36}+\frac{-1}{15}\right]-\frac{2}{9}\)
c, C=\(\left[-\frac{7}{15}\right]\times\frac{5}{8}\times\left[\frac{30}{-7}\right]\times\left[-16\right]\times\left[\frac{-1}{1000}\right]\)
d, D=\(\frac{1}{2}\times\frac{-11}{19}-50\%\times\left[-\frac{1}{19}\right]+\frac{10}{19}\times\frac{1111}{2222}\)
Tính hợp lý:
\(A=\dfrac{7}{12}+\dfrac{5}{12}:6-\dfrac{11}{36}\) \(B=\left(\dfrac{4}{5}+\dfrac{1}{2}\right):\left(\dfrac{3}{13}-\dfrac{8}{13}\right)\)
\(C=\left(\dfrac{2}{3}-\dfrac{1}{4}+\dfrac{5}{11}\right):\left(\dfrac{5}{12}+1-\dfrac{7}{11}\right)\)
\(\frac{3}{\left(x+2\right).\left(x+5\right)}\)+\(\frac{5}{\left(x+5\right).\left(x+10\right)}\)+\(\frac{7}{\left(x+10\right).\left(x+5\right)}\)=\(\frac{x}{\left(x+2\right).\left(x+17\right)}\)
\(\frac{x-1}{2009}\)+ \(\frac{x-2}{2008}\)=\(\frac{x-3}{2007}\) + \(\frac{x-4}{2006}\)
Cho \(A=1+2^1+2^2+2^3+......+2^{2007}\)
a. Tính 2A
b. Chứng tỏ :\(A=2^{2006}-1\)
Cho \(B=1+3+3^2+........+3^{2006}\)
a.Tính 3B
b. Chứng minh :\(B=\left(3^{2007}-1\right):2\)
Cho \(C=1+4+4^2+.....+4^6\)
a.Tính 4C
b. Chứng minh :\(C=\left(4^7-1\right):3\)
\(a,\dfrac{-6}{11}:\left(\dfrac{3}{5}:\dfrac{4}{11}\right)\) b,\(\dfrac{7}{12}+\dfrac{5}{12}:6-\dfrac{11}{36}\)
\(c,\left(\dfrac{4}{5}+\dfrac{1}{2}\right):\left(\dfrac{3}{13}-\dfrac{8}{13}\right)\) \(d,\left(\dfrac{2}{3}-\dfrac{1}{4}+\dfrac{5}{11}\right):\left(\dfrac{5}{12}-1-\dfrac{7}{11}\right)\)
Giúp mik nha:>>