4^x=64
64 : 0,5 + 64 : 0,25 + 64 x 4
64:0,5 + 64:0,25 + 64\(\times4\)
= 64 \(\times\) 2 + 64 \(\times\) 4 + 64 \(\times\) 4
= 64 \(\times\) ( 2 + 4 + 4)
= 64 \(\times\) 10
= 640
a)64^x : 16^x = 256
b)-2401/7^x = -7
c)64/(-4)^x = -256
a) \(64^x:16^x=256\)
\(\Rightarrow\left(2^6\right)^x:\left(2^4\right)^x=2^8\)
\(\Rightarrow2^{6x}:2^{4x}=2^8\)
\(\Rightarrow2^{6x-4x}=2^8\)
\(\Rightarrow2^{2x}=2^8\)
\(\Rightarrow2x=8\)
\(\Rightarrow x=4\)
b) \(\dfrac{-2401}{7^x}=-7\)
\(\Rightarrow\dfrac{-7^4}{7^x}=-7\)
\(\Rightarrow-7^{4-x}=-7\)
\(\Rightarrow7^{4-x}=7\)
\(\Rightarrow4-x=1\)
\(\Rightarrow x=4-1\)
\(\Rightarrow x=3\)
c) \(\dfrac{64}{\left(-4\right)^x}=-256\)
\(\Rightarrow\left(-4\right)^x=\dfrac{64}{-256}\)
\(\Rightarrow\left(-4\right)^x=-4\)
\(\Rightarrow\left(-4\right)^x=\left(-4\right)^1\)
\(\Rightarrow x=1\)
\(a) 64^x:16^x=256\\\Rightarrow (64:16)^x=256\\\Rightarrow 4^x=4^4\\\Rightarrow x=4\\---\)
\(b,\dfrac{-2401}{7^x}=-7\)
\(\Rightarrow7^x=-2401:\left(-7\right)\)
\(\Rightarrow7^x=343\)
\(\Rightarrow7^x=7^3\)
\(\Rightarrow x=3\)
\(c,\dfrac{64}{\left(-4\right)^x}=-256\)
\(\Rightarrow\left(-4\right)^x=64:\left(-256\right)\)
\(\Rightarrow\left(-4\right)^x=-\dfrac{1}{4}\)
\(\Rightarrow\left(-4\right)^x=\left(-4\right)^{-1}\)
\(\Rightarrow x=-1\)
#\(Toru\)
Biểu thức (x-4)^2 - 2(x^2-16) + (x+4)^2 sau khi rút gọn có kết quả là:
A.64 B.4x^2 C.8 D.-64
tìm x (x - 4) ^4 = 64
`@` `\text {Ans}`
`\downarrow`
`(x - 4)^3 = 64?`
`=> (x - 4)^3 = 4^3`
`=> x - 4 = 4`
`=> x = 4 +4 `
`=> x = 8`
Vậy, `x = 8.`
rút gọn biểu thức A=(x+y)(x^2+y^2)(x^4+y^4)...(x^64+y^64) với x-y=1.
các bn lm giúp mk nhá.
\(A=1.\left(x+y\right)\left(x^2+y^2\right)...\left(x^{64}+y^{64}\right)\)
\(=\left(x-y\right)\left(x+y\right)\left(x^2+y^2\right)...\left(x^{64}+y^{64}\right)\)
\(=\left(x^2-y^2\right)\left(x^2+y^2\right)\left(x^4+y^4\right)...\left(x^{64}+y^{64}\right)\)
\(=\left(x^4-y^4\right)...\left(x^{64}+y^{64}\right)\)
\(=...=\left(x^{64}-y^{64}\right)\left(x^{64}+y^{64}\right)=x^{128}-y^{128}\)
tính nhanh:
a) 612 x 64 - 60/4 + 671 - 64
b) 256 + 399 x 255/ 256 x 399 - 143
\(4^{x+1}=64^x\)
\(\Leftrightarrow4^{x+1}=4^{3x}\\ \Leftrightarrow x+1=3x\\ \Leftrightarrow2x=1\\ \Leftrightarrow x=\dfrac{1}{2}\)
Tìm x :
4^x-5 + 4^x=64
4^x-5 + 4^x=64
4x : (4.4.4.4.4)+ 4x . 4=64
4x : ( 45+4)=64
4x : 46 = 64
4x : 4096=64
4x =64 . 4096= 262144
4x =49
Vậy x = 9
49 =262144
27:x-23:x+4 mũ 4:64=216
\(27:x-23:x+4^4:64=216\)
\(\left(27-23\right):x+4^4:4^3=216\)
\(4:x+4=216\)
\(4:x=216-4\)
\(4:x=212\)
\(x=212.4\)
\(x=848\)
Vậy \(x=848\)
64 mũ 3 x 4 mũ 8 x 16 mũ 4
=262144x65536x65536
643 x 48 x 164
= (26)3 \(\times\) (22)8 \(\times\) (24)4
= 218 \(\times\) 216 \(\times\) 216
= 250