\(=\dfrac{1.3\left(1-2\right)}{2.6}-\dfrac{5}{12}=\dfrac{-1}{2}-\dfrac{5}{12}=\dfrac{-11}{12}\)
\(=\dfrac{1.3\left(1-2\right)}{2.6}-\dfrac{5}{12}=\dfrac{-1}{2}-\dfrac{5}{12}=\dfrac{-11}{12}\)
1)Tính
A=\(1+\dfrac{1}{2}\left(1+2\right)+\dfrac{1}{3}\left(1+2+3\right)+...+\dfrac{1}{16}\left(1+2+3+...+16\right)\)
a)1/6x + 1/10x - 4/15x + 1=0
b)(1/7x - 2/7)(-1/5x + 3/5)(1/3x + 4/3)=0
c)(x - 1/3)(y - 1/2)(z - 5)=0 và x + 2=y + 1=z + 3
1.a) A= \(\left(\dfrac{1}{2}-1\right).\left(\dfrac{1}{3}-1\right)...\left(\dfrac{1}{n-1}-1\right).\left(\dfrac{1}{n}-1\right),n\)thuộc N*
b) B= (\(\left(\dfrac{1}{2^2}-1\right).\left(\dfrac{1}{3^2}-1\right)...\left(\dfrac{1}{n^2}-1\right)\); n thuộc N*
a, 5/4 -3/2 . 7/4 - 5/6 b,tính tổng A = 1^2 +3^2 +5^2 +..+(2n-1)^2 Không cần diễn giải ( kết quả thôi ) :))
Tính
A=\(\dfrac{\dfrac{1}{3}-\dfrac{1}{7}-\dfrac{1}{13}}{\dfrac{2}{3}-\dfrac{2}{7}-\dfrac{2}{13}}.\dfrac{\dfrac{3}{4}-\dfrac{3}{16}-\dfrac{3}{64}-\dfrac{3}{256}}{1-\dfrac{1}{4}-\dfrac{1}{16}-\dfrac{1}{64}}+\dfrac{5}{8}\)
3. So sánh
a) A = 1/2019 - 3/11^2 - 5/11^3 - 7/11^4 và B = -1/2019 - 7/11^2 - 5/11^3 - 3/11^4
b) A = 2006/2007 - 2007/2008 + 2008/2009 - 2009/2010 và B = -1/2006.2007 - 1/2008.2009
a) A= \(\dfrac{1}{3}-\dfrac{3}{4}-\left(-\dfrac{3}{5}\right)+\dfrac{1}{72}-\dfrac{2}{9}-\dfrac{1}{36}+\dfrac{1}{15}\)
b) B=\(\dfrac{1}{5}-\dfrac{3}{7}+\dfrac{5}{9}-\dfrac{2}{9}+\dfrac{7}{13}-\dfrac{2}{11}-\dfrac{5}{9}+\dfrac{3}{7}-\dfrac{1}{5}\)
c) C=\(\dfrac{1}{100}-\dfrac{1}{100.99}-\dfrac{1}{99.98}-\dfrac{1}{98.97}-......-\dfrac{1}{3.2}-\dfrac{1}{2.1}\)
Tính A, biết:
\(A=\left(1+\dfrac{1}{1+2}\right)\left(1+\dfrac{1}{1+2+3}\right)\left(1+\dfrac{1}{1+2+3+4}\right)...\left(1+\dfrac{1}{1+2+3+...+996}\right)\left(1+\dfrac{1}{1+2+3+...+997}\right)\)Lưu ý giữa các dấu ngoặc là dấu nhân \(\left(.\right)\), không phải dấu cộng. Vì nếu dấu cộng thì dễ rồi. Giúp mình với
Bài 1 : Thực hiện phép tính
a) ( -1/2) - ( -3/5) + ( -1/9) + 1/71 - ( -2/7) + 4/35 - 7/18
b) ( 3 - 1/4 +2/3) - ( 5 - 1/3 - 6/5 ) - (6 - 7/4 +3/2 )
Bài 2 : Thực hiện phép tính
a) 2/3 - 4 . ( 1/2 +3/4 )
b) ( -1/3 +5/6) .11 -7
c) ( -5/9) . 3/11 + ( -13/18) . 3/11
d) ( -2/3) . 3/11 + ( -16/9) . 3/11
CÁC BẠN CỐ GẮNG HỘ MK NHA :(((
AI NHANH NHẤT HỨA TICK <3 <3 <3
TKS M.N TRƯỚC AK =v=
a)\(\dfrac{\dfrac{2}{3}-}{\dfrac{8}{3}-}\dfrac{\dfrac{2}{5}+}{\dfrac{8}{5}+}\dfrac{\dfrac{2}{7}-}{\dfrac{8}{7}-}\dfrac{\dfrac{2}{9}+}{\dfrac{8}{9}+}\dfrac{\dfrac{2}{11}}{\dfrac{8}{11}}\)
b)\(\left(\dfrac{1}{2}-1\right)\left(\dfrac{1}{3}-1\right)\left(\dfrac{1}{4}-1\right)...\left(\dfrac{1}{50}-1\right)\left(\dfrac{1}{51}-1\right)\)