1, Tính
(6.\(\left(\frac{-1}{3}\right)^2\)-3.\(\left(\frac{-1}{3}\right)\)+1):\(\left(\frac{-1}{3}-1\right)^2\)
2 , Cho biểu thức A = \(-\frac{1}{3}\)+\(\frac{1}{3^2}\)\(-\frac{1}{3^3}\)+\(\frac{1}{3^4}\)\(-\frac{1}{3^5}\)+........+\(\frac{1}{3^{100}}\). Chứng tỏ rằng |A|<\(\frac{1}{4}\)
3,tính giá trị biểu thức : A = 2.\(x^2\)-3x+5 với |x|>\(\frac{1}{2}\)
LÀM ĐƯỢC CÂU NÀO THÌ CỨ LÀM ĐI NHA CÁC BẠN
tính giá trị biểu thức
A=\(\frac{\left[1+2+3+......+100\right].\left[\frac{1}{2}-\frac{1}{3}-\frac{1}{4}-\frac{1}{5}\right].\left[2,4.42-21.4,8\right]}{1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+....+\frac{1}{100}}\)
Bài 1: Thu gọn
a) \(\frac{1}{5}x^4y^3-3x^4y^3\)
b) \(5x^2y^5-\frac{1}{4}x^2y^5\)
c) \(\frac{1}{7}x^2y^3.\left(-\frac{14}{3}xy^2\right)-\frac{1}{2}xy.\left(x^2y^{\text{4}}\right)\)
d) \(\left(3xy\right)^2.\left(-\frac{1}{2}x^3y^2\right)\)
e) \(-\frac{1}{4}xy^2+\frac{2}{5}x^2y+\frac{1}{2}xy^2-x^2y\)
f) \(\frac{1}{2}x^4y.\left(-\frac{2}{3}x^3y^2\right)-\frac{1}{3}x^7y^3\)
g) \(\frac{1}{2}x^2y.\left(-10x^3yz^2\right).\frac{1}{4}x^5y^3z\)
h) \(4.\left(-\frac{1}{2}x\right)^2-\frac{3}{2}x.\left(-x\right)+\frac{1}{3}x^2\)
i) \(1\frac{2}{3}x^3y.\left(\frac{-1}{2}xy^2\right)^2-\frac{5}{4}.\frac{8}{15}x^3y.\left(-\frac{1}{2}xy^2\right)^2\)
k) \(-\frac{3}{2}xy^2.\left(\frac{3}{4}x^2y\right)^2-\frac{3}{5}xy.\left(-\frac{1}{3}x^4y^3\right)+\left(-x^2y\right)^2.\left(xy\right)^2\)
n) \(-2\frac{1}{5}xy.\left(-5x\right)^2+\frac{3}{4}y.\frac{2}{3}\left(-x^3\right)-\frac{1}{9}.\left(-x\right)^3.\frac{1}{3}y\)
m) \(\left(-\frac{1}{3}xy^2\right)^2.\left(3x^2y\right)^3.\left(-\frac{5}{2}xy^2z^3\right)^{^2}\)
p) \(-2y.\left|2\right|x^4y^5.\left|-\frac{3}{4}\right|x^3y^2z\)
cho biểu thức: \(A=\left(\frac{-1}{3}\right)+\frac{1}{3^2}-\frac{1}{3^3}+...+\frac{1}{3^{100}}\)
tính \(B=4\left|A\right|+\frac{1}{3^{100}}\)
tính
a)\(\left(1-\frac{1}{1+2}\right).\left(1-\frac{1}{1+2+3}\right).\left(1-\frac{1}{1+2+3+4}\right).....\left(1-\frac{1}{1+2+3+...+20}\right)\)
b)\(\frac{\left(1+2+3+...+100\right).\left(12.3,4-6,86\right)}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+\frac{1}{6}}\)
c)(18.123+9.436.2+3.5310.6):1+4+7+...+100-410)
giúp mk vs mai mk kiểm tra rồi . ai đúng mk tick nha
Tính giá trị biểu thức:
\(\left[18\frac{1}{6}-\left(0,06:7\frac{1}{2}+3\frac{2}{5}.0,85\right)\right]\) \(:\left(16-2\frac{2}{3}:4\frac{3}{4}\right)\)
1.thực hiện phép tính
a.\(25.\left(\frac{-1}{5}\right)^3+\frac{1}{5}-2.\left(\frac{-1}{2}\right)^2-\frac{1}{2}\)
b.\(35^1_6:\left(\frac{-4}{5}\right)-46^1_6:\left(\frac{-4}{5}\right)\)
c.\(\left(\frac{-3}{4}+\frac{2}{5}\right):\frac{3}{7}+\left(\frac{3}{5}+\frac{-1}{4}\right):\frac{3}{7}\)
d.\(\frac{7}{8}:\left(\frac{2}{9}-\frac{1}{18}\right)+\frac{7}{8}.\left(\frac{1}{36}-\frac{5}{12}\right)\)
e.\(\frac{1}{6}+\frac{5}{6}.\frac{3}{2}-\frac{3}{2}+1\)
f.\(\left(-0,75-\frac{1}{4}\right):\left(-5\right)+\frac{1}{15}-\left(\frac{-1}{5}\right):\left(-3\right)\)
Bài 1: Thực hiện phép tính
a) \(2\frac{1}{2}-\frac{4}{3}+\left(\frac{-1}{3}\right)^4\)
b) \(\frac{1}{7}-\left(-\frac{3}{14}\right)+\frac{1}{2}\)
c) -12:\(\left(\frac{3}{4}-\frac{5}{6}\right)^2\)
d) \(\left(2^2:\frac{4}{3}-\frac{1}{2}\right).\frac{6}{5}-17\)
Bài 2:Tìm x biết
a) \(\frac{4}{7}-x=\frac{1}{3}\)
b) \(x-\frac{2}{3}=-\frac{6}{7}\)
c) \(\left|x-5\right|=7\)
d) \(\frac{2}{3}-1\frac{4}{15}x=\frac{-3}{5}\)
Tìm đa thức M , biết :
a) \(M-\left(\frac{1}{2}x^2y-5xy^2+x^3-y^3\right)=\frac{3}{4}xy^2-2x^2y+\)\(2y^3-\frac{1}{3}x^3\)
b)\(\left(-\frac{1}{3}x^3y^3+5x^2y^2-\frac{5}{2}xy\right)-M=xy-\frac{1}{6}x^3y^3-3x^2y^2\)
c)\(\left(\frac{2}{7}xy^4-5x^5+7x^2y^3-3\right)+M=0\)
1. Tìm giá trị nhỏ nhất, giá trị lớn nhất của các biểu thức sau :
\(A=5+\left|\frac{1}{3}-x\right|\)
\(B=2\left|x-\frac{2}{3}\right|-1\)
\(C=2-\left|x+\frac{2}{3}\right|\)
\(D=3-\frac{5}{2}\left|\frac{2}{5}-x\right|\)
