[tex]\huge\text{Slope: $\boxed{-\frac{3}{5}}$}\\\huge\text{$y$-intercept: $\boxed{9}$}[/tex]
We need to convert this line to slope-intercept form, or [tex]y=mx+b[/tex], where [tex]m[/tex] is the slope and [tex]b[/tex] is the y-intercept.
[tex]\begin{aligned}3x+5y&=45&&\smash{\Big|}&&\text{Start with the original equation.}\\5y&=-3x+45&&\smash{\Big|}&&\text{Subtract $3x$ from both sides.}\\y&=\boxed{-\frac{3}{5}}x+\boxed{9}&&\smash{\Big|}&&\text{Divide everything by $5$.}\end{aligned}[/tex]