Let's assume you meant y = (-2/5)x - 3.
-2/5x could be misinterpreted.
First, clear out the fraction(s). To do this, mult. both sides of the above eq'n by 5.
Result: 5y= -2x - 15. Add 2x to both sides. The resulting equation is what you wanted: an equation in the form Ax + By = C (standard form).
