Question

Tìm x, biết:

2^x+2.3^x+1.5^x=10800

Answer 1

`2^(x+2) . 3^(x+1) . 5^x = 10800`

`=> 2^x. 2^2. 3^x. 3. 5^x=10800`

`=> (2.3.5)^x. (4.3)=10800`

`=> 30^x. 12=10800`

`=> 30^x=10800:12`

`=> 30^x=900`

`=> 30^x=30^2`

`=> x=2`

Answer 2

\(2^{x+2}.3^{x+1}.5^x=10800\\ 2^x.2^2.3^x.3.5^x=10800\\30^x.12=10800\\ 30^x=10800:12\\ 30^x=900\\ 30^x=30^2\\ x=2\)