a) \(3x-13=2\)
\(\Rightarrow3x=2+13\)
\(\Rightarrow3x=15\)
\(\Rightarrow x=15:3\)
\(\Rightarrow x=5\)
Vậy \(x=5\)
b) \(27-\left(5x+4\right)=13\)
\(\Rightarrow5x+4=27-13\)
\(\Rightarrow5x+4=14\)
\(\Rightarrow5x=14-4\)
\(\Rightarrow5x=10\)
\(\Rightarrow x=10:5\)
\(\Rightarrow x=2\)
Vậy \(x=2\)
c) \(2.5^x-33=2^3+3^2\)
\(\Rightarrow2.5^x-33=8+9\)
\(\Rightarrow2.5^x-33=17\)
\(\Rightarrow2.5^x=17+33\)
\(\Rightarrow2.5^x=50\)
\(\Rightarrow5^x=50:2\)
\(\Rightarrow5^x=25\)
\(\Rightarrow5^x=5^2\)
\(\Rightarrow x=2\)
Vậy \(x=2\)
