a) \(70-5\left(x-3\right)=45\)
\(5\left(x-3\right)=25\\ x-3=5\\ x=8\)
b) \(10+2x=4^5:4^3\)
\(10+2x=4^2\\ 10+2x=16\\ 2x=6\\ x=3\)
c) \(130-\left(100+x\right)=25\)
\(100+x=105\\ x=5\)
d) \(175+\left(30-x\right)=200\)
\(30-x=25\\ x=5\)
a.
\(70-5\left(x-3\right)=45\)
\(\Leftrightarrow5\left(x-3\right)=25\)
\(\Leftrightarrow x-3=5\)
\(\Leftrightarrow x=8\)
b.
\(10+2x=4^5:4^3\)
\(\Leftrightarrow10+2x=4^2\)
\(\Leftrightarrow10+2x=16\)
\(\Leftrightarrow2x=6\)
\(\Leftrightarrow x=3\)
c.
\(130-\left(100+x\right)=25\)
\(\Leftrightarrow100+x=105\)
\(\Leftrightarrow x=5\)
d.
\(175+\left(30-x\right)=200\)
\(\Leftrightarrow30-x=200-175\)
\(\Leftrightarrow30-x=25\)
\(\Leftrightarrow x=30-25\)
\(\Leftrightarrow x=5\)
