+33615 3*(x-4.5)5 = 80
Divide both sides by 3
(x - 4.5)5 = 80/3
Take the fifth root of both sides
x - 4.5 = (80/3)1/5
Add 4.5 to both sides
$${\mathtt{x}} = {\left({\frac{{\mathtt{80}}}{{\mathtt{3}}}}\right)}^{\left({\frac{{\mathtt{1}}}{{\mathtt{5}}}}\right)}{\mathtt{\,\small\textbf+\,}}{\mathtt{4.5}} \Rightarrow {\mathtt{x}} = {\mathtt{6.428\: \!385\: \!008\: \!005\: \!254\: \!5}}$$
.
+33615 3*(x-4.5)5 = 80
Divide both sides by 3
(x - 4.5)5 = 80/3
Take the fifth root of both sides
x - 4.5 = (80/3)1/5
Add 4.5 to both sides
$${\mathtt{x}} = {\left({\frac{{\mathtt{80}}}{{\mathtt{3}}}}\right)}^{\left({\frac{{\mathtt{1}}}{{\mathtt{5}}}}\right)}{\mathtt{\,\small\textbf+\,}}{\mathtt{4.5}} \Rightarrow {\mathtt{x}} = {\mathtt{6.428\: \!385\: \!008\: \!005\: \!254\: \!5}}$$
.
