Exercise 66 Page 287

To write an equation of the given line in standard form, we will rearrange the given equation such that the variable terms will be on the left-hand side and the constant on the right-hand side. Since the given equation has decimal coefficients, we will start by multiplying each side of the equation by $10.$ Then we will use inverse operations to rearrange the equation into the standard form.

$y=\text{-}3x-2.5$

MultEqn

$\text{LHS}\cdot 10=\text{RHS}\cdot 10$

$10y=\text{-}30x-25$

AddEqn

$\text{LHS}+30x=\text{RHS}+30x$

$30x+10y=\text{-}25$

DivEqn

$\text{LHS}/5=\text{RHS}/5$

$6x+2y=\text{-}5$

Our equation is now written in standard form with all integer coefficients.

$$\begin{array}{c}6x+2y=\text{-}5\end{array}$$