4.2x-3=125
4.2x=125+3
4.2x=128
2x=128:4
2x=32
2x=25
-> x=5
vậy x=5
\(4.2^x-3=125\)
\(4.2^x=125+3\)
\(4.2^x=128\)
\(2^x=128:4\)
\(2^x=32\)
\(\Rightarrow2^x=2^5\)
\(\Rightarrow x=5\)
Vậy \(x=5\)
Chúc bạn học tốt !!!
\(4.2^x-3=125\)
\(4.2^x=125+3\)
\(4.2^x=128\)
\(2^x=128\div4\)
\(2^x=32\)
\(2^x=2^5\)
\(x=5\)
Vậy x = 5
\(4.2^x-3=125\)
\(\Leftrightarrow4.2^x=125+3\)
\(\Leftrightarrow4.2^x=128\)
\(\Leftrightarrow2^x=128:4\)
\(\Leftrightarrow2^x=32\)
\(\Leftrightarrow2^x=2^5\)
\(\Leftrightarrow x=5\)