rut gon bieu thuc
B=1/2+(1/2)^2+(1/2)^3+...+(1/2)^99
cho bieu thuc p=(x+1)(x+√x)/√x-x-√x, voi x>0
a/ rut gon bieu thuc
b/ tim gia tri cua x de gia tri cua bieu thuc p bang 2
rut gon bieu thuc:(1/2+1)(1/3+1)(1/4+1).....(1/99+1)
Bài này có rắc rối đâu em?
Thực hiện phép tính trong ngoặc lại là ra dạng (n+1)/n.
1 dãy các số liên tục kéo dài nhân với nhau thì triệt tiêu là xong!
Chúc em học tốt!
Rut gon bieu thuc sau:T=(1/2+1).(1/3+1). (1/4+1)....(1/98+1).(1/99+1)
\(T=\frac{3.4.5.6.....100}{2.3.4.5.6.....99}\)
Rút ra nhé:
\(T=\frac{100}{2}\)
T=50.
Chúc em học tốt^^
rut gon bieu thuc sau:
a) 34^2+35^2+........+100^2
b)1^2+3^2+5^2+...+99^2
rut gon bieu thuc
3(2^2+1).(2^4+1)...(2^64+1)+1
\(3\left(2^2+1\right).\left(2^4+1\right)...\left(2^{64}+1\right)+1\)
\(=\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)...\left(2^{64}+1\right)+1\)
\(=\left(2^4-1\right)\left(2^4+1\right)....\left(2^{64}+1\right)+1\)
\(=\left(2^8-1\right).\left(2^8+1\right)\left(2^{16}+1\right)....\left(2^{64}+1\right)+1\)
\(=\left(2^{64}-1\right).\left(2^{64}+1\right)+1\)
\(=2^{64}-1+1=2^{64}\)
Vậy : \(3\left(2^2+1\right).\left(2^4+1\right)...\left(2^{64}+1\right)+1=2^{64}\)
Rut gon bieu thuc
3(2^2+1)(2^4+1)(2^8+1)(2^16+1)
=\(\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)
=\(\left(2^4-1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)
=...=2^32-1
nhân hết ra là xong:))
bài về nhà hs phải tự làm
Cái bước (22-1)(22 + 1)(24 +1)(216+1) làm như thế nào mà ra vậy
Rut gon bieu thuc sau
3(2*2+1)(2*4+1)(2*8+1)(2*16+1)
Rut gon bieu thuc
A= 1+1/2+1/2^+1/2^+....+1/2^2017
\(A=1+\dfrac{1}{2}+\dfrac{1}{2^2}+...+\dfrac{1}{2^{2017}}\)
\(\Rightarrow2A=2+1+\dfrac{1}{2}+\dfrac{1}{2^2}+...+\dfrac{1}{2^{2016}}\)
\(\Rightarrow2A-A=\left(2+1+\dfrac{1}{2}+\dfrac{1}{2^3}+...+\dfrac{1}{2^{2016}}\right)\)
\(-\left(1+\dfrac{1}{2}+\dfrac{1}{2^2}+...+\dfrac{1}{2^{2017}}\right)\)
\(\Rightarrow A=2-\dfrac{1}{2^{2017}}=\dfrac{2^{2018}-1}{2^{2017}}\)
\(A=1+\dfrac{1}{2}+\dfrac{1}{2^2}+...+\dfrac{1}{2^{2017}}\)
\(2A=\left(2+1+\dfrac{1}{2}+...+\dfrac{1}{2^{2016}}\right)\)
\(2A-A=\left(2+1+\dfrac{1}{2}+...+\dfrac{1}{2^{2016}}\right)-\left(1+\dfrac{1}{2}+\dfrac{1}{2^2}+...+\dfrac{1}{2^{2017}}\right)\)
\(A=2-2^{2017}\)
rut gon bieu thuc (6x-1)^2+(6x+1)^2-2(1+6x)(6x+1)