A=(4+1)(4^2+1)(4^4+1)(4^8+1)(4^16+1)(4^32+1)
B=4^64-1
CMR:B=3A
Tính A=(4^2+1)(4^4+1)(4^8+1)(4^16+1)(4^32+1)-1/15 . 4^64
Cho A=(4+1)(42+1)(44+1)(48+1)...(432+1)
B=464-1
CMR B=3A
Ta có: \(A=\left(4+1\right)\left(4^2+1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\left(4^{32}+1\right)\)
\(\Rightarrow3A=3\left(4+1\right)\left(4^2+1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\left(4^{32}+1\right)\)
\(\Rightarrow3A=\left(4-1\right)\left(4+1\right)\left(4^2+1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\left(4^{32}+1\right)\)
\(\Rightarrow3A=\left(4^2-1\right)\left(4^2+1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\left(4^{32}+1\right)\)
\(\Rightarrow3A=\left(4^4-1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\left(4^{32}+1\right)\)
\(\Rightarrow3A=\left(4^8-1\right)\left(4^8+1\right)\left(4^{16}+1\right)\left(4^{32}+1\right)\)
\(\Rightarrow3A=\left(4^{16}-1\right)\left(4^{16}+1\right)\left(4^{32}+1\right)\)
\(\Rightarrow3A=\left(4^{32}-1\right)\left(4^{32}+1\right)\)
\(\Rightarrow3A=4^{64}-1\)
mà \(B=4^{64}-1\)
Vậy \(B=3A\)
A=(4^2+1)(4^4+1)(4^8+1)(4^16+1)(4^32+1)−1/15 . 4^64
Ta có (42 - 1)(42 + 1) = 44 - 1
Ta có 15A = (42 - 1)(42 + 1)(44 + 1)(48 + 1)(416 + 1)(432 + 1) - 464 = 464 - 1 - 464 = -1
=> A = \(\frac{-1}{15}\)
Ghi lại cái đề cho rõ hơn đi t giải cho
Cái đề đọc không ra.Ghi lại cái đề cho rõ hơn đi t giải cho
CM B=3A với:
\(B=4^{32}+1\)
\(A=\left(4+1\right)\left(4^2+1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\)
Sửa B=432-1
Ta có: \(3A=\left(4-1\right)\left(4+1\right)\left(4^2+1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\)
\(=\left(4^2-1\right)\left(4^2+1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)=\left(4^4-1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\)
\(=\left(4^4-1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)=\left(4^8-1\right)\left(4^8+1\right)\left(4^{16}+1\right)\)
\(=\left(4^{16}-1\right)\left(4^{16}+1\right)=4^{32}-1=B\) (đpcm)
1+1+2+2+4+4+8+8+16+16+32+32+64+64=?
bk nha@ >_0
1+1+2+2+4+4+8+8+16+16+32+32+64+64=254
1.Chứng minh rằng a)1/2-1/4+1/8-1/16+1/32-1/64<1/3 b)1/3-2/3^2+3/3^3-4/3^4+...+99/3^99-100/3^100<3/16
CMR:
a)1/2-1/4+1/8-1/16+1/32-1/64<1/3
b)1/3 - 2/3^2 + 3/3^3 - 4/3^4 +...+ 99/3^99 -100/3^100 < 3/16
cmr
a) 1/2 -1/4+1/8-1/16+1/32-1/64 <1/3
b) 1/3-2/3^2+3/3^3-4/3^4+...+99/3^99-100/3^100<3/16
a)234 x 4 + 234 x 5 + 234
b)135 x16 - 135 x 2 - 4 x 135
c) 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64
a,234.4+234.5+234=234(4+5+1)=234.10=2340
b,135.16-135.2-135.4=135(16-4-2)=135.10=1350
c,1/2+1/4+1/8+1/16+1/32+1/64=1-1/2+1/2-1/4+1/4-1/8+1/8-1/16+1/16-1/32=1-1/32=31/32
a) 234 x4 + 234 x 5 + 234 = 234 x ( 1+4+5)=2340
b)135 x16 -135 x2 -4 x135 =135 x (16-2-4) =1350
a) 234.(4+5+1)=234.10=2340
b)135.(16-2-4)=135.10=1350