b; \(\Leftrightarrow2^x=32\)
hay x=5
c: \(\Leftrightarrow\left(7x-11\right)^3=800+200=1000\)
=>7x-11=10
=>7x=21
hay x=3
`a)x` đâu ?
`b)2^x - 15=17`
`2^x=17+15`
`2^x=32`
`2^x=2^^5`
`=>x=5`
`c)(7x-11)^3=2^5.5^2+200`
`(7x-11)^3=800+200`
`(7x-11)^3=1000`
`(7x-11)^3=(10)^3`
`7x-11=10`
`7x=10+11`
`7x=21`
`x=21:7`
`x=3`
\(a,2.3^{^x}=162\)
\(3^{^x}=162:2\)
\(3^{^x}=81\)
\(3^{^x}=3^{^4}\)
\(x=4\)
_______________
\(b,2^x-15=17\)
\(2^x=17+15\)
\(2^x=32\)
\(2^x=2^5\)
\(x=5\)
_________________
\(c\left(7x-11\right)^3=2^5.5^2+200\)
\(\left(7x-11\right)^3=1000\)
\(\left(7x-11\right)^3=10^3\)
\(7x-11=10\)
\(7x=10+11\)
\(7x=21\)
\(x=21:7\)
\(x=3\)
a) \(2\cdot3^2=162\)
\(2\cdot9=162\)
`=>18=162`
đề bài tìm `x` mà ko thấy `x` đâu
b) \(2^x-15=17\)
\(2^x=17+15\)
\(2^x=32\)
\(2^x=2^5\)
`=>x=5`
c) \(\left(7x-11\right)^3=2^5\cdot5^2+200\)
\(\left(7x-11\right)^3=32\cdot25+200\)
\(\left(7x-11\right)^3=1000\)
\(\left(7x-11\right)^3=10^3\)
`=>`\(7x-11=10\)
\(7x=21\)
`=>x=21/7`
`=>x=3`
