rút gọn biểu thức:
\(A=12\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(A=\frac{1}{2}\left(5^2-1\right)\) \(\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
A= 1/2(5^4-1)(5^4+1)(5^8+1)(5^16+1)
Làm tương tự còn:
A=1/2(5^16-1)(5^16+1)=1/2(5^32-1)
1/ Tìm số tự nhiên nhỏ nhất có 3 chữ số sao cho chia cho 11 dư 5 ; chia cho 13 dư 7
2/ Chứng minh rằng : \(10^n+5^3⋮9\)
3/ Tìm x, y \(\in N\) biết : \(\left(x+1\right)\left(2y-5\right):143\)
Bài 2:
10^n có tổng các chữ số là 1
5^3 có tổng các chữ số là 8
=>10^n+5^3 có tổng các chữ số là 9
=>10^n+5^3 chia hết cho 9
Rút gọn biểu thức: P= 12.(\(\left(5^2+1\right).\left(5^4+1\right).\left(5^8+1\right).\left(5^{16}+1\right)\)
\(P=12.\left(5^2+1\right).\left(5^4+1\right).\left(5^8+1\right).\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^2-1\right)\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^4-1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^8-1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^{16}-1\right)\left(5^{16}+1\right)\)
\(=\frac{5^{32}-1}{2}\)
Rút gọn biểu thức ;
\(P=12\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(P=12\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^2-1\right)\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^4-1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^8-1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^{16}-1\right)\left(5^{16}+1\right)\)
\(=\frac{5^{32}-1}{2}\)
rút gọn biểu thức:
P = \(12\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
Rút gọn biểu thức
\(P=12\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
dặt tổng là P
P= 12.(52+1)(54+1)(58+1)(516+1)
=>2P=24.(52+1)(54+1)(58+1)(516+1)
=(52-1)(52+1)(54+1)(58+1)(516+1)
=(54-1)(58+1)(516+1)
=(58-1)(58+1)(516+1)
=(516-1)(516-1)
=532-1
=>(532-1 ):2
\(P=12\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(2P=24\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\left(5^2-1\right)\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\left(5^4-1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\left(5^8-1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\left(5^{16}-1\right)\left(5^{16}+1\right)\)
\(=5^{32}-1\)
đặt tổng là P
P= 12.(52+1)(54+1)(58+1)(516+1)
=>2P=24.(52+1)(54+1)(58+1)(516+1)
=(52-1)(52+1)(54+1)(58+1)(516+1)
=(54-1)(58+1)(516+1)
=(58-1)(58+1)(516+1)
=(516-1)(516-1)
=532-1
=>P=\(\frac{5^{32}-1}{2}\)
Rút gọn biểu thức:
P = \(12\left(5^2+1\right)\left(5^4+1\right)\)\(\left(5^8+1\right)\left(5^{16}+1\right)\)
2p=24(5^2+1)(5^4+1)(5^8+1)(5^16+1)
=(5^2-1)(5^2+1)(5^4+1)(5^8+1)(5^16+1)
=(5^4-1)(5^4+1)(5^8+1)(5^16+1)
=(5^8-1)(5^8+1)(5^16+1)
=(5^16-1)(5^16+1)
=5^32-1
~> p=5^32-1/2
1. Rút gọn biểu thức :
\(\left(x-y+z\right)^2+\left(z-y\right)^2+2\left(x-y+z\right)\left(y-z\right)\)
( Có công thức mấy bạn ghi ra giúp tớ với )
2. Biết số tự nhiên a chia cho 5 dư 4. C/m a^2 chia cho 5 dư 1
3. Tìm giá trị lớn nhất của các đa thức :
a) A= 4x-x^2+3
b) B= x- x^2
c) F= 2x-2x^2-5
1.(x-y+z)2+(z-y)2+2(x-y+z)(y-z)= (x-y+z)+2(x-y+z)(y-z)+(y-z)2=(x-y+z+y-z)2=x2
CT : (A+B)2=A2+2AB+B2
Ta có : A = 4x - x2 + 3
=> A = -(x2 - 4x - 3)
=> A = -(x2 - 4x + 4 - 7)
=> A = -(x2 - 4x + 4) + 7
=> A = -(x - 2)2 + 7
Vì : \(-\left(x-2\right)^2\le0\forall x\)
=> A = -(x - 2)2 + 7 \(\le7\forall x\)
Vậy Amax = 7 khi x = 2
Rút gọn biểu thức
P= \(12\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(P=\frac{1}{2}\left(5^2-1\right)\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^4-1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^8-1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^{16}-1\right)\left(5^{16}+1\right)\)
\(=\frac{1}{2}\left(5^{32}-1\right)\)
Ta có: \(P=12\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(\Leftrightarrow P=\frac{\left(5^2-1\right)}{2}\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(\Leftrightarrow P=\frac{1}{2}\left(5^2-1\right)\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(\Leftrightarrow P=\frac{1}{2}\left(5^4-1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(\Leftrightarrow P=\frac{1}{2}\left(5^8-1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(\Leftrightarrow P=\frac{1}{2}\left(5^{16}-1\right)\left(5^{16}+1\right)\)
\(\Leftrightarrow P=\frac{5^{32}-1}{2}\)
Vậy \(P=\frac{5^{32}-1}{2}\)
