Đáp án:
`a)` `x=4.`
`b)` `x=5^19.`
`c)` `x=2^14.`
Giải thích các bước giải:
`a)` `x\times2^2=2^4.`
`=> x=2^4:2^2.`
`=> x=2^(4-2).`
`=> x=2^2.`
`=> x=4.`
Vậy `x=4.`
`b)` `5^5\times5^4:5^8\timesx=5^21.`
`=> 5^(5+4-8)\timesx=5^21.`
`=> 5^1\timesx=5^21.`
`=> x=5^21:5^1.`
`=> x=5^(21-1).`
`=> x=5^20.`
Vậy `x=5^20.`
`c)` `8^2\times2^5\timesx=2^25.`
`=> (2^3)^2\times2^5\timesx=2^25.`
`=> 2^6\times2^5\timesx=2^25.`
`=> 2^11\timesx=2^25.`
`=> x=2^25:2^11.`
`=> x=2^(25-11).`
`=> x=2^14.`
Vậy `x=2^14.`