Đại số lớp 6
Các câu hỏi tương tự
Chứng minh rằng với k \(\in\) N* ta luôn có \(k\left(k+1\right)\left(k+2\right)-\left(k-1\right)k\left(k+1\right)=3k\left(k+1\right)\)
Cho : \(\left|x\right|+\left|x+1\right|+\left|x+2\right|+\left|x+3\right|=6x\)
a. Chứng minh : x \(\ge\) 0
b. Tìm x thỏa mãn
Chứng minh rằng với mọi \(n\in N\); \(n\ge2\) ta có :
\(\dfrac{3}{9.14}+\dfrac{3}{14.19}+....................+\dfrac{3}{\left(5n-1\right)\left(5n+4\right)}< \dfrac{1}{15}\)
Chứng minh rằng với mọi \(n\in N\); \(n\ge2\) ta có :
\(\dfrac{3}{9.14}+\dfrac{3}{14.19}+\dfrac{3}{19.24}+..........+\dfrac{3}{\left(5n-1\right)\left(5n+4\right)}< \dfrac{1}{15}\)
Help me!!!!!!!!!!!!!!!!!!
chứng minh rằng
\(\frac{2}{n.\left(n+1\right).\left(n+2\right)}=\frac{1}{n.\left(n+1\right)}-\frac{1}{\left(n+1\right).\left(n+2\right)}\)
áp dụng tính
A = \(\frac{1}{1.2.3}+\frac{1}{2.3.4}+..............+\frac{1}{2015.2016.2017}\)
chứng minh rằng
\(\frac{2}{n.\left(n+1\right).\left(n+2\right)}=\frac{1}{n.\left(n+1\right)}-\frac{1}{\left(n+1\right).\left(n+2\right)}\)
áp dụng tính
A=\(\frac{1}{1.2.3}+\frac{1}{2.3.4}+.............+\frac{1}{2015.2016.2017}\)
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)\(\dfrac{1}{x\left(x+1\right)\left(x+2\right)}-\dfrac{1}{\left(x+1\right)\left(x+2\right)\left(x+3\right)}=\dfrac{3}{x\left(x+1\right)\left(x+2\right)\left(x+3\right)}\)
Chứng minh rằng :
\(\dfrac{2}{n\left(n+2\right)}=\dfrac{1}{n}-\dfrac{1}{n+2}\)
biết( n,a thuộc n*)
chứng minh: \(\dfrac{a}{n\left(n+a\right)}=\dfrac{1}{n}-\dfrac{1}{n+a}\)