Có nghĩa là giá trị tuyệt đối đó bn
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Đại số lớp 6
Các câu hỏi tương tự
\(\frac{\left(2.4.6.....2016\right).\left(2.4.6.....2016\right)}{\left(1.3.5.....2015\right).\left(3.5.7.....2017\right)}\) rút gọn bằng gì vậy?
Tính nhanh :
\(\dfrac{\left(12:13\right)+\left(12:131\right)-\left(12:1313\right)+\left(12:13131\right)}{\left(15:13\right)+\left(15:131\right)-\left(15:1313\right)+\left(15:13131\right)}\)
Chứng minh rằng :
a)dfrac{1}{x}-dfrac{1}{x+a}dfrac{a}{xleft(x+aright)}
b)dfrac{1}{xleft(x+1right)}-dfrac{1}{left(x+1right)left(x+2right)}dfrac{2}{xleft(x+1right)left(x+2right)}
c)dfrac{1}{xleft(x+1right)left(x+2right)}-dfrac{1}{left(x+1right)left(x+2right)left(x+3right)}dfrac{3}{xleft(x+1right)left(x+2right)left(x+3right)}
Đọc tiếp
Chứng minh rằng :
a)\(\dfrac{1}{x}\)-\(\dfrac{1}{x+a}=\dfrac{a}{x\left(x+a\right)}\)
b)\(\dfrac{1}{x\left(x+1\right)}-\dfrac{1}{\left(x+1\right)\left(x+2\right)}=\dfrac{2}{x\left(x+1\right)\left(x+2\right)}\)
c)\(\dfrac{1}{x\left(x+1\right)\left(x+2\right)}-\dfrac{1}{\left(x+1\right)\left(x+2\right)\left(x+3\right)}=\dfrac{3}{x\left(x+1\right)\left(x+2\right)\left(x+3\right)}\)
Tìm x, biết:
\(\dfrac{2}{\left(x-1\right)\left(x-3\right)}+\dfrac{5}{\left(x-3\right)\left(x-8\right)}+\dfrac{12}{\left(x-8\right)\left(x-20\right)}-\dfrac{1}{x-20}=\dfrac{-1}{4}\)
Bài 2: Chứng minh bất đẳng thức:
a) \(\left(a+b+c+d\right)-\left(a-b-c+d\right)+1=a-\left(a-2b-2c-d\right)+\left(d+1\right)\)
b)\(\left(4x-3y+2\right)-\left(3x-4y+2\right)=\left(2x+2y\right)-\left(x+y\right)\)
Thu gọn các tích sau:
a) \(P=\left(3x+3x+...+3x\right)\) ( 100 SH ) \(\cdot\left(5y+5y+...+5y\right)\) ( 8 SHạng )
b) \(Q=\left(-2a\right)\cdot\left(-2a\right)\) ( 15 thừa số -2a ) \(\cdot...\cdot\left(-2a\right)\cdot\left(5b\right)\cdot\left(5b\right)\cdot...\cdot\left(5b\right)\) ( 15 thừa số 5b )
BT2: Tính nhanh
15) \(1000-\left\{\left(-5\right)^3.\left(-2\right)^3-11.\left[7^2-5.2^3+8.\left(11^2-121\right)\right]\right\}\)
Tìm STN x biết rằng:
a)\(720:[41-\left(2x-5\right)]=2^3\cdot5\)
b)\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)+...+\left(x+100\right)=5+50\)
d)\(\left(x+3\right)^{10}=\left(x-3\right)^{17}\)
Tính : T = \(\left(1-\frac{1}{4}\right)\cdot\left(1-\frac{1}{9}\right)\cdot\left(1-\frac{1}{16}\right)\cdot....\left(1-\frac{1}{576}\right)\cdot\left(1-\frac{1}{625}\right)\)