What we are going to do is to reverse the process of putting an equation in slope intercept form...
y = -3/5x +3 (the 3 needs to be a fraction with denominator of 5)
y = -3/5x + 15/5 (now, let's multiply each side by 5 to remove fractions)
5y = -3x + 15 (add 3x to each side of the equation)
3x + 5y = 15 (this is now in standard form)
