Answer by Mimiwhatsup:
[tex]\mathrm{Switch\:sides}\\5x+5y=d\\\mathrm{Subtract\:}5x\mathrm{\:from\:both\:sides}\\5x+5y-5x=d-5x\\Simplify\\5y=d-5x\\\mathrm{Divide\:both\:sides\:by\:}5\\\frac{5y}{5}=\frac{d}{5}-\frac{5x}{5}\\\mathrm{Simplify}\\y=\frac{d-5x}{5}[/tex]
