Hey there!
To start, first isolate y by dividing both sides by 5:
(5y = -2/3x + 5)/5
=
y = (-2/3)(1/5)x + 1 = -2/15x + 1
Because linear equations are always in the form of y = mx + b where m is the slope, the slope of the equation is -2/15.
Hope this helps!