Chapter 4 - Section 4.2 - Solving Systems of Linear Equations by the Substitution Method - Exercise Set - Page 302: 63

$$-4x + 20y = -12$$

Let us write the equation to include multiplying both sides by $-4$: $$-4(x - 5y) = -4(3)$$ Let's use distributive property to get rid of the parentheses: $$(-4)(x) - (4)(-5y) = -4(3)$$ Let's multiply out the terms: $$-4x + 20y = -12$$